I'd say go for a Casio G-Shock. I have been able to ruin a Sector Watch before but not a G-Shock yet. When I was in UK for rescue boat training I broke my Sector. Then my friend gave me a an Army watch which only lasted one and a half days. The very same day I bought a G-Shock. I am stil using it. I have done lots of heavy field work with it. The best part is it is cheap.

Burak