Seiko Prospex SPB155 (Baby Alpinist) vs Tissot PRX Powermatic 80

Side-by-side comparison of specifications and features

SeikoProspex

SPB155 (Baby Alpinist)

TissotPRX Powermatic 80

T137.407.11.041.00

Key Differences

Best Value

Seiko Prospex (Ref. SPB155 (Baby Alpinist))

Starting from $475

Best Water Resistance

Seiko Prospex (Ref. SPB155 (Baby Alpinist))

200m (2x more)

Price Comparison

Seiko Prospex

MSRP

$725

New

$475

Used

$319

Tissot PRX Powermatic 80

MSRP

$695

New

$788

Used

$626

MSRP New (Amazon) Used (eBay)

Comparison of Seiko Prospex, Tissot PRX Powermatic 80
Specification	Seiko Prospex	Tissot PRX Powermatic 80
Pricing
MSRP	$725	$695
New Price	$475	$788
Used Price (Low)	$319	$626
Used Price (High)	$5,700	$1,067
30-Day Trend	↑ +21.6%	↑ +1.8%
Used Price Range	$319 - $5,700	$626 - $1,067
Identity
Reference	SPB155 (Baby Alpinist)	T137.407.11.041.00
Nickname	N/A	N/A
Style	Field, Sports, Tool	Sports, Dress
Release Era	2010s	2020s
Dimensions
Diameter	38mm	40mm
Thickness	N/A	10.9mm
Lug Width	N/A	12mm
Lug to Lug	N/A	44.6mm
Movement
Movement	Automatic	Automatic
Power Reserve / Battery	N/A	N/A
Accuracy	N/A	N/A
Case
Case Material	Stainless Steel	Stainless Steel
Crystal	Sapphire Crystal	Sapphire Crystal
Water Resistance	200m (diving)	100m (recreational diving)
Bezel	Fixed	Fixed
Dial
Dial Color	Green	Blue
Luminous	Yes	Yes
Community
Review Rating	N/A	N/A
In Collections	N/A	N/A
On Wishlists	N/A	N/A
Forum Threads	N/A	N/A

Quick Summary

Seiko Prospex SPB155 (Baby Alpinist) and Tissot PRX Powermatic 80 can overlap on price or use case, but the buying decision usually comes down to wrist presence versus easier fit, water-ready utility versus dressier everyday wear, field character versus sports versatility. They both touch the sports use case, so smaller spec differences can matter more than brand preference.

How to choose

The biggest practical difference is usually movement and upkeep. Start with wrist fit and movement preference, then use water resistance and price to break the tie.

Seiko Prospex SPB155 (Baby Alpinist)

Seiko Prospex SPB155 (Baby Alpinist) is a better fit for smaller wrists, mechanical-watch enthusiasts, field styling.

Tissot PRX Powermatic 80

Tissot PRX Powermatic 80 is a better fit for buyers who want more wrist presence, mechanical-watch enthusiasts, sports styling.

Key Differences

Movement and upkeep

Seiko Prospex SPB155 (Baby Alpinist): automatic movement

Tissot PRX Powermatic 80: 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

Tissot PRX Powermatic 80: 40mm · L2L 44.6mm · 138g

Fit is a real separator here — compare case width and lug-to-lug before deciding, especially if wrist comfort matters more than headline features.

Water resistance

Seiko Prospex SPB155 (Baby Alpinist): 200m

Tissot PRX Powermatic 80: 100m

Water resistance is a meaningful separator here — the higher-rated option gives more flexibility for swimming or rougher daily use.

Price and value

Seiko Prospex SPB155 (Baby Alpinist): $475

Tissot PRX Powermatic 80: $695

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

Tissot PRX Powermatic 80: sports

Seiko Prospex SPB155 (Baby Alpinist) leans more field, while Tissot PRX Powermatic 80 pulls toward sports use case — pick the one that matches how you will actually wear it.

Crystal and materials

Seiko Prospex SPB155 (Baby Alpinist): sapphire crystal · steel

Tissot PRX Powermatic 80: sapphire crystal · steel

Materials are broadly similar, so finish, fit, and price will matter more than the materials list alone.

Choose Seiko Prospex SPB155 (Baby Alpinist) If...

You want a smaller case footprint on the wrist.
Swimming, beach use, or tougher daily wear is part of the plan.
You are specifically shopping for a field style watch.

Choose Tissot PRX Powermatic 80 If...

You prefer more dial presence and a larger case feel.
You are specifically shopping for a sports style watch.
You are comfortable paying more for a stronger feature set.

Price and Value Notes

Seiko Prospex SPB155 (Baby Alpinist) is often the value play at current pricing, while Tissot PRX Powermatic 80 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.

Where to Check Deals

Check current deals on Amazon and eBay using the buttons below — listing prices, seller quality, and condition can change quickly.

Check current deals on Amazon and eBay

Prices change often, so compare the latest listings and condition options before you buy.

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Seiko Prospex

Check Price on AmazonOpens in new tab · Price may vary

Check Price on eBayFrom $638 · Live listings

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Tissot PRX Powermatic 80

Check Price on AmazonOpens in new tab · Price may vary

Check Price on eBayFrom $794 · Live listings

Affiliate links — WatchCompared earns a commission on qualifying purchases. This doesn't affect your price.

Comparison FAQ

Which one is better for smaller wrists?

Seiko Prospex SPB155 (Baby Alpinist) — it is 38mm wide versus 40mm.

Which is better for swimming or rough daily wear?

Seiko Prospex SPB155 (Baby Alpinist) — it is rated 200m versus 100m. Both are in the same broad bracket, so treat this as a tiebreaker rather than a deciding factor.

Is the more expensive one worth it?

Seiko Prospex SPB155 (Baby Alpinist) is the value pick at roughly $220 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.