Youre on the right track, Casey. A wet suit or good paddle jacket is probably just the thing your husband needs.
The Mission Drysuit
Of course, if you really love him, you will get him a dry suit, not a wet suit. The difference is articulated in the name. A wet suit lets water seep into the suit, trapping a thin layer of water next to the skin. Body heat then warms the water, the neoprene of the suit provides insulation, and you stay warm...for a while. In time, cold water will circulate into the suit, and the wearer gets chilled.
A dry suit, on the other hand, is waterproof by design. You put on long underwear to fit the conditions (if its colder, wear more), put on the suit, and you are good to go. This kind of suit offers a big comfort boost over a wet suit, and if youre in the water or getting splashed a lot, you stay warmer much longer.
The trade-off, of course, is cost. A good dry suit, such as the NRS Mission Drysuit (made with waterproof/breathable eVent fabric) runs $850. Models made from Gore-Tex are about the same cost.
Wet suits are much more affordable, and really very effective as protection against occasional spray, and can act as an emergency flotation/heat-retaining device if your husband goes into the drink. The O'Neill Epic II 4/3mm wet suit, for instance, is only $160 and is a very good-quality suit.
Paddling jackets are designed to provide sort of half the protection of a full dry suit. Worn over Farmer John wet suits or other lower-body protection, they work great. A real good one is Kokatats GTX Paclite Jacket ($175), and is made from waterproof/breathable Gore Paclite material. A nice piece.