Seiko Prospex SPB155 (Baby Alpinist) vs Zelos Mako V3

Side-by-side comparison of specifications and features

SeikoProspex

SPB155 (Baby Alpinist)

ZelosMako V3

Mako-V3-Ti

Key Differences

Best Value

Seiko Prospex (Ref. SPB155 (Baby Alpinist))

Starting from $475

Best Water Resistance

Zelos Mako V3 (Mako-V3-Ti)

300m (2x more)

Slimmest

Seiko Prospex (Ref. SPB155 (Baby Alpinist))

12.9mm thick

Biggest Price Drop

Seiko Prospex (Ref. SPB155 (Baby Alpinist))

-8.6% in 30 days

Price Comparison

Seiko Prospex

MSRP

$725

New

$475

Used

$389

Zelos Mako V3

MSRP

$699

New

$750

Used

$600

MSRP New (Amazon) Used (eBay)

Comparison of Seiko Prospex, Zelos Mako V3
Specification	Seiko Prospex	Zelos Mako V3
Pricing
MSRP	$725	$699
New Price	$475	$750
Used Price (Low)	$389	$600
Used Price (High)	$5,700	$1,079
30-Day Trend	↓ -8.6%	↑ +4.0%
Used Price Range	$389 - $5,700	$600 - $1,079
Identity
Reference	SPB155 (Baby Alpinist)	Mako-V3-Ti
Nickname	N/A	N/A
Style	Field, Sports, Tool	Diver, Tool
Release Era	2010s	2020s
Dimensions
Diameter	38mm	40mm
Thickness	12.9mm	13.6mm
Lug Width	20mm	20mm
Lug to Lug	46mm	46mm
Movement
Movement	Automatic	Automatic
Power Reserve / Battery	N/A	N/A
Accuracy	N/A	N/A
Case
Case Material	Stainless Steel	Titanium
Crystal	Sapphire Crystal	Sapphire Crystal
Water Resistance	200m (diving)	300m (diving)
Bezel	Fixed	Unidirectional rotating
Dial
Dial Color	Green	Teal
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

This Seiko Prospex SPB155 (Baby Alpinist) vs Zelos Mako V3 comparison is less about a universal winner and more about wrist presence versus easier fit, water-ready utility versus dressier everyday wear, field character versus diver versatility. Treat it as a value-versus-upgrade decision — confirm the extra spend solves a problem you will notice every week.

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.

Zelos Mako V3

Zelos Mako V3 is a better fit for buyers who want more wrist presence, mechanical-watch enthusiasts, diver styling.

Key Differences

Movement and upkeep

Seiko Prospex SPB155 (Baby Alpinist): automatic movement

Zelos Mako V3: 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

Zelos Mako V3: 40mm · L2L 46mm

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

Zelos Mako V3: 300m

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

Zelos Mako V3: $699

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

Zelos Mako V3: diver

Seiko Prospex SPB155 (Baby Alpinist) leans more field, while Zelos Mako V3 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

Zelos Mako V3: sapphire crystal · titanium

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.
You are specifically shopping for a field style watch.
You want the lower current entry price.

Choose Zelos Mako V3 If...

You prefer more dial presence and a larger case feel.
Swimming, beach use, or tougher daily wear is part of the plan.
You are specifically shopping for a diver style watch.

Price and Value Notes

Seiko Prospex SPB155 (Baby Alpinist) is often the value play at current pricing, while Zelos Mako V3 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 $639 · Live listings

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Zelos Mako V3

Check Price on AmazonOpens in new tab · Price may vary

Check Price on eBayFrom $650 · 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. Thickness is 12.9mm vs 13.6mm, which also affects how it sits.

Which is better for swimming or rough daily wear?

Zelos Mako V3 — it is rated 300m versus 200m. 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 $224 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.