If you're looking for a flexible wetsuit base layer that is going to give you added warmth while you're out in the water - whether on it's own or under a wetsuit.
Yamamoto 39cell SCS coated neoprene
0.5mm neoprene with jersey lining makes this base layer easy to get on and off and comfortable against the skin.
A long body length with a special gripper hem panel helps to keep water out of the base layer and so increase warmth.
A flexy 0.5mm neoprene underarm panel allows for great freedom of movement in this base layer, whether worn by itself or under a wetsuit.