Hamilton Khaki Field Auto vs Seiko Prospex

Side-by-side comparison of specifications and features

HamiltonKhaki Field Auto

H70455533

SeikoProspex

SPB155 (Baby Alpinist)

Key Differences

Best Value

Seiko Prospex (Ref. SPB155 (Baby Alpinist))

Starting from $450

Best Water Resistance

Seiko Prospex (Ref. SPB155 (Baby Alpinist))

200m (2x more)

Biggest Price Drop

Hamilton Khaki Field Auto (H70455533)

-18.1% in 30 days

Price Comparison

Hamilton Khaki Field Auto

MSRP

$695

New

$720

Used

$627

Seiko Prospex

MSRP

$725

New

$450

Used

$319

MSRP New (Amazon) Used (eBay)

Comparison of Hamilton Khaki Field Auto, Seiko Prospex
Specification	Hamilton Khaki Field Auto	Seiko Prospex
Pricing
MSRP	$695	$725
New Price	$720	$450
Used Price (Low)	$627	$319
Used Price (High)	$639	$5,700
30-Day Trend	↓ -18.1%	↑ +2.9%
Used Price Range	$627 - $639	$319 - $5,700
Identity
Reference	H70455533	SPB155 (Baby Alpinist)
Nickname	N/A	N/A
Style	Field, Tool	Field, Sports, Tool
Release Era	2010s	2010s
Dimensions
Diameter	38mm	38mm
Thickness	11mm	N/A
Lug Width	20mm	N/A
Lug to Lug	45.5mm	N/A
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	100m (recreational diving)	200m (diving)
Bezel	Fixed	Fixed
Dial
Dial Color	Black	Green
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

If you are deciding between Hamilton Khaki Field Auto and Seiko Prospex, the real decision is usually about wrist presence versus easier fit, water-ready utility versus dressier everyday wear, entry price versus premium finishing or specs. 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.

Hamilton Khaki Field Auto

Hamilton Khaki Field Auto is a better fit for mechanical-watch enthusiasts, field styling.

Seiko Prospex

Seiko Prospex is a better fit for mechanical-watch enthusiasts, field styling.

Key Differences

Movement and upkeep

Hamilton Khaki Field Auto: automatic movement

Seiko Prospex: 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

Hamilton Khaki Field Auto: 38mm · L2L 45.5mm

Seiko Prospex: 38mm

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

Hamilton Khaki Field Auto: 100m

Seiko Prospex: 200m

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

Price and value

Hamilton Khaki Field Auto: $695

Seiko Prospex: $450

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

Hamilton Khaki Field Auto: field

Seiko Prospex: field

Both lean into a similar field use case — the choice is more about fit, features, and price than category.

Crystal and materials

Hamilton Khaki Field Auto: sapphire crystal · steel

Seiko Prospex: sapphire crystal · steel

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

Choose Hamilton Khaki Field Auto If...

You are comfortable paying more for a stronger feature set.

Choose Seiko Prospex If...

Swimming, beach use, or tougher daily wear is part of the plan.
You want the lower current entry price.

Price and Value Notes

Seiko Prospex is often the value play at current pricing, while Hamilton Khaki Field Auto 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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Hamilton Khaki Field Auto

Check Price on AmazonOpens in new tab · Price may vary

Check Price on eBayFrom $632 · Live listings

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

Seiko Prospex

Check Price on AmazonOpens in new tab · Price may vary

Check Price on eBayFrom $579 · 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?

Start with case width and lug-to-lug. The watch that looks smaller on paper is often the safer choice, but lug shape and thickness still affect how it wears.

Which is better for swimming or rough daily wear?

Use the water resistance row as the first filter. Higher ratings generally give more flexibility for swimming and water exposure, but strap choice and overall condition still matter.

Should I choose based on price alone?

Price matters, but the better buy is the watch that matches your fit, feature priorities, and use case. Check live listings first, then decide whether the price gap actually changes the ownership experience.