Once the suit fills with water you will not be able to swim. In short I would stay away from drysuits for ocean paddling. Wetsuits work even if they are torn. They are less expensive and more attractive. They come in a variety of styles and prices.
Neoprene is a marvel of modern technology.
A good quality wetsuit will last a lifetime. Every paddler will ultimately acquire a wetsuit of some sort. It is one of the best investments in safety one can make, even if it is simply a neoprene cap or a pair of pogies. Chris Ladner is owner of Ecomarine and in a past career was product development manager for FitzWright, the world's largest manufacturer of neoprene garments and makers of BARE wetsuits.