Seiko Black Monster. Google for a pic! Tough as nails, solid bracelet or tough rubber strap, looks a bit odd, but in a good way :-)
Not a chrono or multi-dial, but day/date and amazing lume. £100 will get you a decent secondhand one, but I'd buy new from Creation online. Of all the watches I've had, G shocks are the toughest though - £100 should get you a solar/atomic GW6900 which would be my choice if I was heavy handed. Good luck with the search!