Most likely your cheap tripod will suffer corrosion but good tripod like Gitzo will be ok if you clean it after. As for camera, the problem is not corrosion but if seawater come in contact with camera, most likely it will die infront of you or later. Electronic and salt does not mix.
So to have fun, don't shot. To shot, no fun. Especially if you hold a DSLR and not PnS.