Check out this great article by REI.
To summarize:
- Always wear a personal flotation device (PFD) and never take it off while on the water. If you need to adjust your top layers, find a place to take out instead. You can also “raft up” with a kayak buddy holding your boat firmly while you change, though changing on shore is the better option.
- Dress for the water temperature, not the air temperature; this may mean wearing a wetsuit or dry suit.
- Dress in layers, especially on top.
- Dress for sun protection. Regardless of cloud cover, a day on the water is a day of sun exposure. So wearing clothing with UPF-rated fabrics is a wise choice (plus sunscreen for reflected UV radiation).
- Avoid cotton in all layers, because it absorbs water and stays wet; seek quick-drying fabrics instead. For any clothing layer that touches your skin, go with wicking, quick-drying nylon or polyester (or another synthetic fabric). Wool dries less quickly, but insulates when wet, so is also a fine choice.
- Wear clothes that let you move comfortably and will be comfortable for long periods of sitting.
- Look for abrasion-resistant fabrics that are more rugged and can stand up to the wear and tear of sand, water and any rough materials of your kayak.
- Avoid “rustable” zippers, fasteners and hardware: Water, particularly salt water, corrodes many metals, so rugged plastics are a good alternative. You can probably trust that metal components in paddling-specific gear are corrosion resistant.
