WatchSpecDBwatches, by spec

Citizen Eco-Drive BM8180 vs Orient Defender

Both are field / explorer watches in the entry tier — here's how the specs differ and which to pick.

Last verified 2026-06-11 · specs from manufacturer data · tier = price band, confirm the live price at the retailer

SpecCitizen Eco-Drive BM8180Orient Defender
MovementSolar / light-poweredAutomatic
Water resistance100m100m
Case size37mm42mm
Crystalmineralmineral
StyleField / explorerField / explorer
Price tierEntryEntry

Which should you buy?

Where to buy

Check the Citizen Eco-Drive BM8180 price on Amazon →

Check the Orient Defender price on Amazon →

As an Amazon Associate we earn from qualifying purchases, at no extra cost to you. Affiliate links never affect our specs or which watches we compare.

FAQ

What's the difference between the Citizen Eco-Drive BM8180 and the Orient Defender?
Both are field / explorer watches in the entry tier. The Citizen Eco-Drive BM8180 is solar / light-powered, 100m water resistance, 37mm, mineral crystal; the Orient Defender is automatic, 100m water resistance, 42mm, mineral crystal.

Which is better value, the Citizen Eco-Drive BM8180 or the Orient Defender?
Both sit in the entry tier, so it comes down to movement, water resistance and case size — see the spec table above.

More field / explorer comparisons: Seiko Alpinist SPB121 vs Hamilton Khaki Field Mechanical · Hamilton Khaki Field Mechanical vs Sinn 556 I · Vaer C5 Field vs Seiko 5 Sports Field SRPG35 · Vaer C5 Field vs Lorier Falcon · all field / explorer watches · all comparisons