Seiko SKX007 vs SKX009 vs SKX013: Complete Comparison Guide

Quick Answer:

The Seiko SKX007, SKX009, and SKX013 share the same legendary 7S26 automatic movement and 200m water resistance, but differ in aesthetics and sizing: SKX007 features a 42mm case with classic black dial and black bezel ($300-350 current market); SKX009 is identical in size (42mm) but sports a blue dial with iconic Pepsi bezel (blue/red) at similar pricing ($299-365); SKX013 is the compact variant at 38mm diameter with black dial/bezel configuration, now commanding premium prices ($600+) due to scarcity. All three use 22mm lugs except the SKX013 (20mm), weigh 124-135g, measure 13mm thick, and feature Hardlex crystal with unidirectional rotating bezel. Choose SKX007 for classic black tool watch aesthetics, SKX009 for colorful vintage diver style, or SKX013 for smaller wrists (under 6.5" circumference). All three were discontinued in 2019 but remain highly sought after for their bulletproof reliability, extensive modding potential, and ISO 6425 dive watch certification at formerly accessible prices.

The Seiko SKX lineup represents one of horology's most celebrated dive watch families, discontinued in 2019 yet continuing to dominate secondary markets and modding communities. Understanding the precise differences between the SKX007, SKX009, and SKX013 helps collectors and enthusiasts identify which variant best matches their wrist size, aesthetic preferences, and budget—particularly important as prices diverge in the post-discontinuation market.

At-a-Glance Comparison Table

Key Differences Explained

1. Size: 42mm vs 38mm Cases

The most fundamental distinction separates the standard-size models (SKX007/009) from the compact variant (SKX013):

SKX007 and SKX009 (42mm): Both feature identical 42.5mm diameter cases measuring 13.25mm thick with 46mm lug-to-lug span and 22mm lug width. At 135g, these watches wear like traditional dive watches—substantial without being oppressive, suitable for wrist circumferences from 6.5" to 8". The 46mm lug-to-lug measurement means wearers with 6.75" wrists and above experience optimal proportion, though smaller wrists (down to 6.25") can accommodate them if preferring larger watches.

SKX013 (38mm): The compact sibling measures 38mm diameter with identical 13mm thickness but shorter 44mm lug-to-lug and narrower 20mm lug width. Weighing 124g (11g lighter than the 42mm models), the SKX013 delivers genuine dive watch capability in a package suited for 5.5" to 6.75" wrists. The reduced diameter doesn't compromise water resistance—it retains full 200m rating—but does introduce subtle design changes including slightly more tapered lugs, a slimmer bezel profile, and uniquely shaped hands with arrow-like seconds and minute hands featuring finer tapered points compared to the SKX007's traditional rounded profiles.

Wearability Comparison: The 4mm diameter difference translates to noticeable wrist presence changes. The SKX007/009 provide classic dive watch proportions worn by enthusiasts who appreciate tool watch presence, while the SKX013 addresses the growing market for capable dive watches in vintage-inspired 38mm sizing—a dimension increasingly valued as collectors rediscover 1960s-1970s proportions.

2. Aesthetic Differences: Black vs Pepsi Bezels

SKX007 (All-Black): Features a matte black dial with matching black aluminum bezel insert. The monochromatic color scheme creates a classic tool watch appearance—understated, versatile, suitable for dress-casual contexts beyond dive usage. The black-on-black configuration ages gracefully as bezel aluminum naturally fades, developing patina that enhances vintage character. This variant represents the quintessential "Submariner homage" aesthetic that made the SKX legendary.

SKX009 (Pepsi Bezel): Distinguishes itself with a dark navy blue dial paired with the iconic blue/red "Pepsi" aluminum bezel insert—blue markers from 12 to 6 o'clock (0-30 minutes), red from 6 to 12 o'clock (30-60 minutes). This colorway pays homage to vintage GMT-Master aesthetics while serving practical dive timing functions. The Pepsi configuration appeals to collectors seeking vibrant vintage diver style—more casual and sporting than the SKX007's tool watch severity. The blue dial provides slightly warmer character compared to stark black, and the bezel colors develop rich patina as aluminum oxidizes over time.

SKX013 (All-Black, Compact): Mirrors the SKX007's black dial and black bezel configuration but in 38mm proportions. This creates vintage diver aesthetics reminiscent of 1960s Seiko 62MAS and early Submariner references that prioritized wrist comfort over size. The identical color scheme to the SKX007 means aesthetic choice between these two depends purely on preferred sizing rather than style differences.

3. Hand Design Variations

While often overlooked, the SKX013's hands differ subtly from the SKX007/009:

SKX007 and SKX009 Hands: Feature traditional Seiko dive watch profiles with tapered forms culminating in rounded tips on the seconds hand. The hour and minute hands utilize classic arrow-shaped luminous plots with gentle tapering. These proportions balance visibility against dial real estate in the 42mm case.

SKX013 Hands: Employ uniquely shaped hands with more pronounced aerodynamic arrow-like forms. The seconds and minute hands taper to finer, more delicate points compared to the standard models. This redesign accommodates the 38mm dial diameter, ensuring visual balance and maintaining legibility despite reduced scale. The sharper hand profiles contribute to the SKX013's slightly more refined appearance compared to the tool-watch robustness of larger siblings.

4. Lug Width: 22mm vs 20mm Strap Compatibility

Strap and bracelet selection differs between sizes:

SKX007 and SKX009 (22mm lugs): The wider 22mm lug spacing provides access to extensive aftermarket strap options. This dimension matches industry standards for 42mm+ dive watches, meaning NATO straps, rubber dive straps, leather straps, and aftermarket bracelets exist in abundance. Modders particularly value 22mm width because premium bracelet options (Strapcode, Uncle Seiko) deliver substantial wrist presence matching the case proportions.

SKX013 (20mm lugs): The narrower 20mm lug width still offers abundant strap choices—20mm represents the most common watch strap dimension globally—but aftermarket bracelet options specific to the SKX013 are less numerous compared to 22mm variants. The narrower lugs contribute to sleeker overall proportions, though they limit usage of bracelet options designed specifically for larger SKX models.

5. Weight Difference: 135g vs 124g

The SKX007/009 at 135g versus the SKX013 at 124g creates an 11-gram difference (approximately 8% weight reduction for the compact model). While seemingly minimal, this difference becomes noticeable during extended wear. The lighter SKX013 provides greater comfort during all-day wear, particularly for wearers with smaller wrists who might find the combination of 42mm diameter and 135g weight fatiguing over 12-hour periods. The heavier SKX007/009 delivers more substantial wrist presence—a characteristic some enthusiasts prefer for its tool-watch gravitas, while others consider excessive for daily wear.

What All Three Models Share

Despite the differences outlined above, the SKX007, SKX009, and SKX013 share fundamental characteristics that made the SKX lineup legendary:

Seiko 7S26 Automatic Movement

All three models house the workhorse Seiko Caliber 7S26-0020 automatic movement—a 21-jewel automatic mechanism with 43-hour power reserve running at 21,600 bph (3 Hz frequency). The 7S26 earned its reputation through bulletproof reliability and minimal service requirements, with many SKX watches running 10-15 years before requiring first service. However, the movement lacks modern conveniences: no hacking (seconds hand doesn't stop when crown is pulled), no hand-winding capability (crown in first position doesn't wind the mainspring—winding occurs only via rotor or watch shaking), and ±20 to -30 seconds/day accuracy (typical Seiko automatic specifications, not chronometer grade).

The 7S26's limitations—considered significant when SKX models sold for $200-275—become less concerning in the current market where discontinued examples command $300-750. The lack of hacking and hand-winding matters little to enthusiasts who prize the movement's legendary durability, serviceability, and "set it and forget it" reliability that defined the SKX philosophy: a watch you wear constantly without worrying about accuracy or maintenance.

200m ISO 6425 Dive Watch Certification

All three SKX variants meet ISO 6425 dive watch standards with 200-meter water resistance, unidirectional rotating bezel with 120-click action, luminous hands and indices, and screw-down crown at 4 o'clock position. This certification means these watches aren't merely "water resistant to 200m"—they've passed rigorous testing including pre-aging pressure tests, functionality tests during temperature changes, shock resistance, magnetic resistance, and 200m pressurization. The SKX007, SKX009, and SKX013 represent true tool watches capable of actual recreational diving use, not merely dive-styled fashion pieces.

Hardlex Crystal

All models employ Seiko's proprietary Hardlex crystal—a mineral glass treated to improve scratch resistance and impact tolerance. Hardlex sits between standard mineral crystal and sapphire in durability hierarchy: more scratch-resistant than basic mineral glass but less shatter-resistant than sapphire. In practice, Hardlex develops fine scratches over years of daily wear (particularly from desk diving contact) but resists shattering from impacts that would crack sapphire. Most modders immediately upgrade to sapphire crystals (readily available from CrystalTimes USA, Namoki Mods, and other suppliers), making the Hardlex specification less relevant for long-term SKX owners.

Iconic Design Language

The three models share Seiko's celebrated dive watch design: applied luminous hour markers, day-date display at 3 o'clock with dual-language options (English/Roman, English/Arabic, English/Kanji, etc.), 4 o'clock crown position providing comfort during wrist flexion, and cushion-case architecture with integrated lug design. This aesthetic—refined over decades from Seiko's 1965 62MAS and 1970s 6309 dive watches—balances functionality with restrained elegance, avoiding the aggressive styling common in modern dive watches.

Discontinued Status and Rising Values

Seiko discontinued the entire SKX lineup in 2019, replacing it with the Seiko 5 Sports line (SRPD references) featuring upgraded 4R36 movements (with hacking and hand-winding) at similar price points ($250-350 MSRP). However, the discontinuation elevated SKX models to cult status. Original MSRP of $195-275 has escalated to $300-750 depending on condition and variant, with the SKX013 commanding significant premiums due to scarcity—38mm models were always produced in smaller quantities than 42mm siblings.

Detailed Model Analysis

Seiko SKX007: The Classic Tool Watch

The SKX007 represents the definitive expression of Seiko's dive watch philosophy: unpretentious, functional, reliable, and affordable (originally). The all-black color scheme creates maximum versatility—equally at home on NATO straps for weekend hiking, leather straps for business casual, rubber straps for swimming, or steel bracelets for daily wear. The SKX007's matte black dial provides excellent legibility in low light thanks to generous LumiBrite application on all hour markers and hands, while the black bezel insert ages with character as aluminum naturally fades and develops patina.

Why Choose the SKX007:

• Maximum versatility across casual, sporting, and semi-formal contexts
• Classic tool watch aesthetic that never goes out of style
• Most popular modding base—extensive aftermarket support for cases, dials, hands, bezels
• Lower current market prices compared to SKX009 and SKX013 (typically $300-350 used, $400-500 new old stock)
• Black-on-black configuration shows less visual wear than colorful bezels
• Optimal for wrists 6.5" to 8" circumference

Modding Potential: The SKX007 serves as the most popular Seiko mod base globally. Aftermarket suppliers like Namoki Mods, CrystalTimes USA, Lucius Atelier, and DLW Mods offer hundreds of compatible components: sapphire crystals (flat, domed, double-domed), ceramic bezel inserts (every color imaginable), upgraded dials (gilt, vintage-inspired, modern), hands (Mercedes, sword, snowflake styles), and complete cases in various finishes. Custom builders like SKYRIM WRIST transform SKX007 watches into personalized dive watches with sapphire crystals, ceramic bezels, and pressure-tested water resistance, delivering upgraded specifications while preserving the SKX's beloved design language.

Seiko SKX009: The Pepsi Diver

The SKX009 delivers identical functionality to the SKX007 but with vibrant personality via its Pepsi bezel. The navy blue dial—darker than the bright blues of modern Seiko Prospex models—pairs elegantly with the blue/red bezel, creating vintage-inspired aesthetics reminiscent of 1960s-1970s dive watches when colorful bezels served practical purposes (distinguishing elapsed time at a glance). The Pepsi configuration appeals to enthusiasts who appreciate watches with character and visual warmth beyond black tool watch severity.

Why Choose the SKX009:

• Iconic Pepsi bezel provides instant vintage diver recognition
• Navy blue dial offers warmer, less stark appearance than black
• Colorful aesthetic stands out in collections dominated by black dive watches
• Aluminum bezel develops rich patina as blue and red oxidize differently over time
• Similar pricing to SKX007 (€299-365 used, $450-550 new old stock)
• More casual and sporting than the SKX007's tool watch formality
• Same modding potential as SKX007 with identical case dimensions
• Optimal for wrists 6.5" to 8" circumference

Collector Appeal: The SKX009 has developed dedicated following among collectors who specifically seek Pepsi-bezeled watches without paying Rolex GMT-Master premiums. While not a true GMT (the SKX009 features standard time-only movement), the Pepsi aesthetic connects to horology's GMT heritage. The model's discontinuation has elevated its collectibility—particularly for J2 (Japan-made) variants showing superior finishing compared to K2 (Malaysia) versions.

Seiko SKX013: The Compact Diver

The SKX013 addresses an underserved market: enthusiasts with smaller wrists (or preferences for vintage proportions) who want genuine dive watch capability without 42mm+ sizing. At 38mm diameter with 44mm lug-to-lug, the SKX013 fits comfortably on wrists from 5.5" to 6.75" circumference—demographics often forced to wear watches that overwhelm their proportions or compromise by choosing dress watches lacking dive functionality.

Why Choose the SKX013:

• Genuine 200m ISO 6425 dive certification in compact 38mm sizing
• Perfect for smaller wrists (under 6.75" circumference) without compromising capability
• Lighter weight (124g) improves all-day comfort
• Vintage-inspired proportions matching 1960s dive watch aesthetics
• Identical 7S26 movement and water resistance as larger siblings
• Increasingly rare—always produced in smaller quantities, now discontinued
• Higher current market values ($600-750 used, $800+ new old stock) due to scarcity
• Slightly more refined design details (tapered hands, slimmer bezel) than tool-watch siblings

Modding Considerations: The SKX013 accepts the same NH35/NH36 movement upgrades as larger SKX models, and aftermarket parts exist for dials, hands, bezels, and crystals. However, the smaller case means components must be sized specifically for 38mm proportions—SKX007 dials, for instance, won't fit the SKX013's dial diameter. Suppliers like Namoki Mods, CrystalTimes USA, and DLW Mods offer SKX013-specific parts, though selection is narrower than for 42mm models. The 20mm lug width also limits premium bracelet options compared to the extensive 22mm aftermarket.

Current Scarcity: The SKX013 commands significant price premiums over the SKX007/009 because it was always manufactured in smaller volumes. While the SKX007 and SKX009 remained widely available through 2019 discontinuation, the SKX013 experienced periodic shortages even during production. Post-discontinuation, finding SKX013 examples in good condition proves challenging—particularly unworn new old stock, which commands $800+ when available. This scarcity appeals to collectors but frustrates buyers seeking affordable entry into the SKX ecosystem.

Price Analysis: Original vs Current Market

Historical Pricing (2010-2019)

During production years, all three SKX models maintained consistent MSRP:

• 2010-2015: $195-225 typical retail pricing
• 2015-2018: $225-275 as yen strengthened and demand increased
• 2018-2019: $250-295 in final production year

Gray market sellers frequently offered 20-30% discounts, making SKX watches available for $150-200 through most of their production run. This accessibility—combined with legendary reliability—established the SKX lineup as the default recommendation for entry-level mechanical dive watches, competing against $400-600 Swiss alternatives (Hamilton Khaki Navy, Tissot Seastar) while offering superior water resistance and proven durability.

Current Market Pricing (2025)

Discontinuation transformed SKX models from "affordable beater watches" into collectible timepieces:

SKX007 (Black):

• Used (good condition, 2015-2019 production): $300-350
• Used (excellent condition, minimal wear): $350-425
• New Old Stock (unworn with box/papers): $400-500
• Modified versions with sapphire/ceramic upgrades: $450-650

SKX009 (Pepsi):

• Used (good condition, 2015-2019 production): €299-365 ($320-390 USD)
• Used (excellent condition, minimal wear): $375-450
• New Old Stock (unworn with box/papers): $450-550
• Modified versions with sapphire/ceramic upgrades: $475-700

SKX013 (38mm Black):

• Used (good condition, 2015-2019 production): $600-700
• Used (excellent condition, minimal wear): $700-800
• New Old Stock (unworn with box/papers): $800-1,000+
• Modified versions (rare, as owners avoid modding scarce examples): $850-1,100

Value Trend Analysis: The SKX007 showed initial post-discontinuation appreciation (rising from $275 MSRP to $400-450 in 2020-2021) but has since stabilized around $300-350 for used examples as Seiko 5 Sports models (SRPD references) satisfy demand for affordable automatics. The SKX009 maintains slight premium over the SKX007 due to Pepsi bezel desirability. The SKX013 commands the highest premiums—often 2x-3x the SKX007's price—because 38mm dive watches remain rare in current markets dominated by 42mm+ sizing, and the SKX013's discontinuation eliminated the only affordable compact ISO-certified diver.

Which SKX Should You Choose?

Choose the SKX007 If:

• You want maximum versatility across dress-casual, sporting, and casual contexts
• Classic black tool watch aesthetics appeal more than colorful bezels
• You plan to mod the watch extensively (SKX007 has largest aftermarket support)
• Budget constraints favor the most affordable SKX variant ($300-350 used)
• Your wrist circumference measures 6.5" to 8"
• You prefer understated watches that don't draw attention
• You want a watch that pairs equally well with NATO straps, leather, rubber, and metal bracelets

Choose the SKX009 If:

• You appreciate vintage diver aesthetics with colorful Pepsi bezels
• You want a watch with character and warmth beyond black tool watches
• The navy blue dial appeals more than stark black dials
• You collect Pepsi-bezeled watches (GMT-Master homage without $10,000+ investment)
• Your wrist circumference measures 6.5" to 8"
• You prefer watches that generate conversation and recognition
• Budget allows similar pricing to SKX007 ($320-390 used, €299-365)
• You value aluminum bezel patina development as part of watch aging character

Choose the SKX013 If:

• Your wrist circumference measures 5.5" to 6.75" (or you prefer compact proportions)
• You want genuine 200m dive capability without oversized modern proportions
• 38mm vintage sizing appeals more than contemporary 42mm+ dive watches
• Lighter weight (124g vs 135g) matters for all-day comfort
• You value rarity and collectibility (willing to pay $600-800 premium)
• You appreciate refined design details (tapered hands, slimmer bezel)
• You're building a collection of compact dive watches (rare in current market)
• Budget accommodates 2x-3x the SKX007's price for compact sizing

Wrist Size Guide

Modding Potential Comparison

One reason for the SKX lineup's enduring popularity is exceptional modding potential—the ability to transform stock watches into personalized customs using aftermarket components.

SKX007/009 Modding Ecosystem

The 42mm SKX platform represents the most extensively supported modding base in horology. Aftermarket suppliers offer:

Movement Upgrades: Direct drop-in NH35 (hacking + hand-winding), NH36 (day-date hacking/hand-winding), NH38 (no date with hacking/hand-winding), or NH34 (GMT complication) movements—all compatible with existing dial, hands, and date wheel.

Crystal Options: Flat sapphire, single-domed sapphire, double-domed sapphire, sloped sapphire, beveled sapphire—all with optional anti-reflective coating in blue, clear, or green tints. Suppliers like CrystalTimes USA offer 15+ crystal profiles specifically sized for SKX007/009 cases.

Bezel Inserts: Ceramic inserts in every color (black, blue, green, red, Batman, Pepsi, Root Beer, Coke), aluminum inserts, lumed ceramic inserts, sloped ceramic inserts for vintage aesthetics. DLW Mods and Lucius Atelier produce exclusive designs unavailable elsewhere.

Dials: Hundreds of aftermarket dials including OEM-style, vintage-inspired (gilt markers, tropical patina), modern (forged carbon, meteorite), minimalist, and fantasy designs. Dial options accommodate NH35 (3 o'clock date), NH38 (no date), and NH36 (day-date) movements.

Hands: Mercedes (classic Rolex style), sword (vintage Omega style), snowflake (Tudor style), skeleton, dauphine, broad arrow, and GMT hands for NH34 builds. Swiss Super-LumiNova or C3/BGW9 lume options.

Complete Builds: Custom watch builders like SKYRIM WRIST offer professionally assembled SKX mods with pressure-tested water resistance, warranties, and quality control—delivering upgrade benefits without DIY requirements. These builds typically feature NH35/NH36 movements, sapphire crystals, ceramic bezels, and custom dial/hand configurations at $249-449 depending on specifications.

SKX013 Modding Ecosystem

The SKX013 accepts most of the same upgrades but requires 38mm-specific components:

Available Parts: NH35/NH36/NH38/NH34 movements (identical fitment to SKX007), sapphire crystals sized for 38mm case (CrystalTimes, Namoki Mods, DLW), ceramic bezel inserts for 38mm bezels, and hands compatible with NH movements.

Limited Selection: Dial options for 38mm cases are more restricted—aftermarket suppliers focus primarily on 42mm SKX parts due to higher demand. Some modders resort to custom dial manufacturing or repurposing vintage Seiko dials from similar-sized watches.

Bracelet Limitations: The 20mm lug width limits premium bracelet choices compared to 22mm options. Strapcode and Uncle Seiko offer some 20mm bracelets, but selection is narrower.

Modding Philosophy: Many SKX013 owners avoid extensive modding due to the watch's scarcity and collectibility. Unlike SKX007 watches (abundant and affordable at $300-350, making them ideal mod donors), the SKX013's $600-800 pricing and rarity make owners more cautious about irreversible modifications. Those who do mod SKX013 watches typically limit changes to sapphire crystal upgrades and movement swaps to NH35/NH36 while preserving original dials, bezels, and cases.

Frequently Asked Questions

What is the main difference between SKX007 and SKX009?

The SKX007 and SKX009 are identical in dimensions (42mm case, 13mm thick, 22mm lugs), movement (7S26 automatic), and water resistance (200m). The only difference is aesthetics: SKX007 features an all-black dial with black bezel, while SKX009 has a dark navy blue dial with blue/red Pepsi bezel. Choose SKX007 for classic tool watch appearance or SKX009 for vintage diver style with colorful bezel. Current pricing is similar ($300-390 used).

Is the SKX013 too small compared to SKX007?

The SKX013 isn't "too small"—it's optimally sized for wrists under 6.75" circumference and enthusiasts preferring vintage proportions. At 38mm diameter vs 42mm (SKX007/009), the 4mm difference creates noticeable size variation but doesn't compromise capability: the SKX013 retains full 200m water resistance, identical 7S26 movement, and same features in more compact dimensions. Choose based on wrist size: SKX013 for under 6.75" wrists, SKX007/009 for 6.75"+ wrists. The SKX013's current $600-800 pricing reflects its scarcity, not inferior specification.

Why is the SKX013 more expensive than SKX007 and SKX009?

The SKX013 commands 2x-3x premiums ($600-800 vs $300-350 for SKX007) due to scarcity: Seiko always produced fewer 38mm models than 42mm versions, assuming smaller demand. Post-discontinuation in 2019, this limited supply elevated SKX013 prices as collectors recognized 38mm ISO-certified dive watches are rare in current markets dominated by 42mm+ sizing. Additionally, the SKX013 addresses underserved demographics (smaller wrists, vintage proportion preferences), creating concentrated demand for limited supply. The price premium reflects collectibility and scarcity, not superior quality—all three models share identical movements and certifications.

Can I still buy new SKX watches in 2025?

Seiko discontinued all SKX models in 2019, so "new" examples are New Old Stock (NOS)—unworn watches remaining from final production batches. NOS SKX007/009 command $400-550 when available from specialty dealers and gray market sellers. NOS SKX013 models are exceptionally rare, commanding $800-1,000+ when they surface. Most buyers purchase used SKX watches in excellent condition ($300-700 depending on model) from secondary markets including Chrono24, eBay, WatchExchange (Reddit), and local watch forums. Seiko replaced the SKX with Seiko 5 Sports (SRPD references) featuring upgraded 4R36 movements at similar pricing ($250-350).

Do SKX007 and SKX009 parts interchange?

Yes. The SKX007 and SKX009 share identical cases, movements, crystal dimensions, bezel fitment, hand sizes, and dial dimensions. All internal and external components interchange freely. This means an SKX007 can be converted to SKX009 specifications by swapping the bezel insert (blue/red Pepsi) and dial (navy blue), or vice versa. Aftermarket parts designed for SKX007 fit SKX009 without modification. This interchangeability makes the SKX007/009 the most versatile modding platform, as owners can experiment with different aesthetics using the same base watch.

Is the 7S26 movement in SKX watches outdated?

The 7S26 lacks modern features (no hacking, no hand-winding) but remains exceptionally reliable and serviceable. Introduced in 1996, the caliber proved its durability over 25+ years with minimal failure rates and low service costs ($100-150 typical service intervals of 10-15 years). The movement's simplicity—fewer complications mean fewer failure points—contributes to SKX reliability. For modders, the 7S26 can be directly replaced with NH35/NH36 movements ($40-80) adding hacking and hand-winding without case modifications. The 7S26's "outdated" specifications matter less than its proven track record of bulletproof performance.

Which SKX model is best for modding?

The SKX007 represents the best modding base: it's the most affordable variant ($300-350 used vs $600-800 for SKX013), features the most extensive aftermarket support (hundreds of dials, bezels, hands, cases designed specifically for 42mm SKX), and its all-black aesthetic serves as a blank canvas for any mod direction (vintage, modern, colorful, tactical). The SKX009 offers identical modding potential with same component compatibility. The SKX013's scarcity and high pricing ($600-800) discourage extensive modding—owners preserve originality rather than modify rare examples. For budget-conscious modders building multiple projects, the SKX007's affordability allows experimentation without financial stress.

Are SKX watches good investments?

SKX watches are appreciating assets but shouldn't be purchased purely for investment. The SKX007/009 appreciated from $200-275 MSRP to $300-500 current market (50-100% gains over 5-10 years), while the SKX013 tripled from $250 MSRP to $600-800. However, these gains pale compared to traditional investments (S&P 500 returned 15% annually 2015-2025). Purchase SKX watches because you'll wear and enjoy them—appreciation is a bonus, not the primary rationale. The discontinued status provides some price floor (unlikely to drop below $250-300 for SKX007/009), but these remain tool watches, not luxury investments like Rolex or Patek Philippe experiencing 300-500% appreciation.

What replaced the SKX after discontinuation?

Seiko replaced the SKX lineup with Seiko 5 Sports models (SRPD references) featuring upgraded 4R36 movements (hacking + hand-winding, 41-hour power reserve), ISO 6425 certification, 100m water resistance (downgrade from SKX's 200m), and similar pricing ($250-350 MSRP). Popular replacements include SRPD51 (black dial, black bezel, SKX007 aesthetic), SRPD53 (blue dial, Pepsi bezel, SKX009 aesthetic), and SRPD73 (root beer bezel). While the 5 Sports models offer superior movements, many enthusiasts prefer SKX watches for 200m water resistance, more compact case proportions (42mm vs 42.5mm), and classic design without the prominent "5" logo on dials.

Should I buy a used SKX or a new Seiko 5 Sports?

Buy a used SKX if you prioritize 200m water resistance (vs 100m on 5 Sports), prefer classic SKX aesthetics without prominent branding, want modding potential with the most extensive aftermarket support, or collect discontinued Seiko models with appreciation potential. Buy a new Seiko 5 Sports if you want hacking and hand-winding (4R36 movement), prefer new watch warranties over used examples, value slightly better accuracy (4R36 runs ±15 to -10 sec/day vs 7S26's ±20 to -30 sec/day), or want integrated bracelets with diashield coating. Used SKX007/009 ($300-350) and new SRPD models ($250-350) occupy similar price points—choice depends on prioritizing water resistance/classic design (SKX) versus modern movement features (5 Sports).

Conclusion: Three Legendary Dive Watches, Different Purposes

The Seiko SKX007, SKX009, and SKX013 represent the final iteration of Seiko's most celebrated dive watch platform—a design refined over five decades from the 1965 62MAS through the 6309/7548 generations to the ultimate 7S26-powered SKX family. While they share fundamental DNA—the bulletproof 7S26 movement, 200m ISO 6425 certification, Hardlex crystal, day-date display, and unidirectional bezel—the three variants serve distinct purposes in collections and on wrists.

The SKX007 delivers pure tool watch functionality in understated black-on-black configuration, maximizing versatility across casual, sporting, and semi-formal contexts while providing the most affordable entry ($300-350 used) into the discontinued SKX ecosystem. Its status as the definitive modding platform—supported by the most extensive aftermarket catalog in affordable watchmaking—makes it the default choice for enthusiasts who view watches as customizable canvases rather than static collector pieces.

The SKX009 preserves the SKX007's specifications and dimensions while injecting personality via its iconic Pepsi bezel and navy dial—aesthetics connecting to vintage dive watch heritage from an era when colorful bezels provided functional benefits beyond style. This variant appeals to collectors seeking character and warmth in dive watches without the stark severity of all-black tool watches, and who appreciate aluminum bezel patina development as watches age naturally over decades of wear.

The SKX013 addresses the underserved market for genuine dive capability in compact 38mm proportions suited to smaller wrists and vintage-inspired preferences. While commanding significant premiums ($600-800) due to production scarcity, the SKX013 represents the only affordable ISO-certified dive watch in this dimension—a specification increasingly rare as modern manufacturers chase 42mm+ sizing. Its refined design details and collectibility elevate it beyond mere "smaller SKX007" status into a distinct model with dedicated following.

As discontinued models appreciating in secondary markets, these three SKX variants occupy unique positions: affordable enough to remain accessible ($300-800 depending on variant), proven reliable enough to serve as daily tool watches, and collectible enough to preserve or appreciate in value. Whether you choose the versatile SKX007, characterful SKX009, or compact SKX013 depends on wrist size, aesthetic preferences, and budget—but any choice connects you to horology's most successful affordable dive watch legacy, a platform that demonstrated mechanical watches could be simultaneously robust, beautiful, and accessible without $1,000+ pricing.

For those seeking customized SKX builds without DIY assembly, custom watch builders like SKYRIM WRIST offer handcrafted SKX-based dive watches with upgraded NH35/NH36 movements, sapphire crystals, ceramic bezels, and pressure-tested water resistance—preserving the SKX's legendary design while incorporating modern component improvements. These builds deliver the best of both worlds: classic SKX aesthetics combined with contemporary specifications and warranties.