Tons will work, but educate yourself.
I always lean towards Pentax/Ricoh DSLRs for kayaking for a few reasons. The prices are great, the weather sealing is great, and they are rugged enough to withstand the abuse that we put on them. I've had a few different ones. There are a few made with magnesium bodies that are great here in Colorado. The K-5 series and the K-3 series are the toughest, but somewhat more expensive with the body alone costing between $500 and $900. The good news is the lenses are cheaper than Canon and Nikon because the image stabilization is in the body instead of each lens. WR lenses are worth investing in, and I've been using these cameras for a long time, and never had a malfunction!