Going the DSLR route will be very expensive. You do have to get weathersealed lenses to go along with the weathersealed camera. The cheapest route would be to get a Pentax K10, K20, or K200 with a Pentax 16-50mm DA* lens. The lens alone runs $744, but you could find one of those bodies and the lens for less than $1500. The problem is that it's not much reach for zooming.

If you want to go the point and shoot route then there are a number of choices. Here is a comparison review of the weathersealed cameras.

http://www.dpreview.com/reviews/Q209waterproofgroup/page17.asp