Side-by-side comparison of specifications and features
Compare visual case presence and physical footprint on one shared wrist. Measure your top-down wrist width for a stronger result; lug-to-lug is used when the catalog has it.
Medium (6.7″)
Estimated top width: 56.7 mm
Preliminary range: 54.7–61.8 mm.
Watch A
Visual presence
ModerateCase covers 67% of your modeled wrist width.
Physical footprint
Clear spaceEstimated clearance: 5.3 mm per side.
Watch B
Visual presence
BoldCase covers 70% of your modeled wrist width.
Physical footprint
Clear spaceEstimated clearance: 4.4 mm per side.
Proportional guide only: visual presence and physical footprint do not predict comfort. Weight, thickness, caseback shape, rigid lugs, strap stiffness, wrist-bone prominence, wearing tension, bezel design, and case curvature change how a watch actually wears.
Start with the specifications that meaningfully differ. Expand the complete table for reference details and missing-data context.
| Specification | Seiko Prospex | Traska Freediver III |
|---|---|---|
| Pricing | ||
| MSRPProspex is $10 less at MSRP | $725 | $735 |
| Used Price (Low)Prospex is $281 less at the low end | $319 | $600 |
| Used Price (High) | $3,750 | $745 |
| 30-Day Trend | ↑ +31.6% | 0.0% |
| Used Price Range | $319 - $3,750 | $600 - $745 |
| Identity | ||
| Style | Field, Sports, Tool | Diver, Tool |
| Dimensions | ||
| DiameterProspex is 1.8mm smaller | 38mm | 39.8mm |
| ThicknessProspex is 0.3mm thinner | 12.9mm | 13.2mm |
| Lug to Lug | 46mm | 47.8mm |
| Case | ||
| Bezel | Fixed | Unidirectional rotating |
| Dial | ||
| Dial Color | Green | Black |
2 fields are excluded from the differences view because one watch lacks comparable data. Use “All specs” to inspect those gaps.
Seiko Prospex SPB155 (Baby Alpinist) and Traska Freediver III can look close on a spec sheet, yet the tradeoffs that matter most are usually field character versus diver versatility. They both touch the tool use case, so smaller spec differences can matter more than brand preference.
Bottom line
There is a real price gap here — treat the more expensive option as an upgrade decision and confirm whether the extra spend buys something you will notice in weekly use. Choose Seiko Prospex SPB155 (Baby Alpinist) if you are specifically shopping for a field style watch; choose Traska Freediver III if you are specifically shopping for a diver style watch.
Choose Seiko Prospex SPB155 (Baby Alpinist) when
Seiko Prospex SPB155 (Baby Alpinist) is a better fit for smaller wrists, mechanical-watch enthusiasts, field styling.
Choose Traska Freediver III when
Traska Freediver III is a better fit for buyers who want more wrist presence, mechanical-watch enthusiasts, diver styling.
Movement and upkeep
Seiko Prospex SPB155 (Baby Alpinist): automatic movement
Traska Freediver III: automatic movement
Both use the same movement type, so maintenance differences are limited and fit or feature details should decide the purchase.
Size and wearability
Seiko Prospex SPB155 (Baby Alpinist): 38mm · L2L 46mm · 144g
Traska Freediver III: 39.8mm · L2L 47.8mm
Their size profiles are relatively close, so fit comes down to shape, weight, and how each watch sits on your wrist.
Water resistance
Seiko Prospex SPB155 (Baby Alpinist): 200m
Traska Freediver III: 200m
Water resistance is similar on paper, so focus on fit, features, and price instead.
Price and value
Seiko Prospex SPB155 (Baby Alpinist): $540
Traska Freediver III: $735
There is a real price gap here — treat the more expensive option as an upgrade decision and confirm whether the extra spend buys something you will notice in weekly use.
Style and use case
Seiko Prospex SPB155 (Baby Alpinist): field
Traska Freediver III: diver
Seiko Prospex SPB155 (Baby Alpinist) leans more field, while Traska Freediver III pulls toward diver use case — pick the one that matches how you will actually wear it.
Crystal and materials
Seiko Prospex SPB155 (Baby Alpinist): sapphire crystal · steel
Traska Freediver III: sapphire crystal · steel
Materials are broadly similar, so finish, fit, and price will matter more than the materials list alone.
Seiko Prospex SPB155 (Baby Alpinist) and Traska Freediver III get compared constantly because both are tool watches, they are within 1.8mm of each other in case width, they share the same automatic movement — so the spec sheet alone will not tell you which to buy.
Seiko Prospex SPB155 (Baby Alpinist) for most buyers — Lug-to-lug is 46mm on Seiko Prospex SPB155 (Baby Alpinist) and 47.8mm on Traska Freediver III; that, more than case width, decides whether it overhangs a smaller wrist.
Seiko Prospex SPB155 (Baby Alpinist) is often the value play at current pricing, while Traska Freediver III makes more sense if you will use its extra features regularly.
There is a real price gap here — treat the more expensive option as an upgrade decision and confirm whether the extra spend buys something you will notice in weekly use.
Check current deals on Amazon and eBay using the buttons below — listing prices, seller quality, and condition can change quickly.
Prices change often, so compare the latest listings and condition options before you buy.
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Seiko Prospex
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Traska Freediver III
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Seiko Prospex SPB155 (Baby Alpinist) — it is 46mm lug-to-lug versus 47.8mm, and lug-to-lug is what decides whether a watch overhangs a smaller wrist.
They are rated the same, so water resistance will not decide this. Choose on strap material and how much you mind scratching the case.
Seiko Prospex SPB155 (Baby Alpinist) is the value pick at roughly $196 less. Pay more only if a specific difference above matters to you — otherwise the cheaper one is the smarter buy. Confirm live listings, since marketplace pricing moves.
Lug-to-lug is 46mm on Seiko Prospex SPB155 (Baby Alpinist) and 47.8mm on Traska Freediver III; that, more than case width, decides whether it overhangs a smaller wrist. That is the difference you will notice day to day; the rest of the specs are close enough not to matter.
Seiko Prospex SPB155 (Baby Alpinist) for most buyers — Lug-to-lug is 46mm on Seiko Prospex SPB155 (Baby Alpinist) and 47.8mm on Traska Freediver III; that, more than case width, decides whether it overhangs a smaller wrist.
Evidence & Method
This page currently relies on normalized catalog fields and calculated differences. No external reviewer observation is used in its verdict.
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