Neoprene socks

Socks do three jobs. They keep the feet warm, and cold feet cramp, which in long fins is a real problem twenty metres from the rock. They stop the fin pocket rubbing the heel and the instep raw over a long session. And they fill the pocket so that the kick transfers to the blade with no play.

They also let you walk over rock to the water without cutting your feet.

Neoprene, 3 mm for most of the year on the Moroccan coast, 5 mm for the Atlantic in winter, 1.5 to 2 mm for the Mediterranean in summer or for a diver whose fin pocket is already tight.

What matters:

• A sole with some grip and reinforcement, for the walk over rock and for the wear inside the pocket.
• Glued and blind-stitched seams, so water does not pump in at the ankle.
• A cut that comes above the ankle and under the suit trousers.
• Enough stretch to go on easily over a dry foot.

Some divers use a thin lycra or nylon sock inside the neoprene one to make the fins easier to put on. Fin keepers, straps over the heel, are a separate item and worth having in surf.

Buy the socks before the fins, or bring them when you try fins on. The fin pocket size depends entirely on the sock thickness, and a 5 mm sock takes a whole size more than a 3 mm one. Snug with no folds at the toes or the heel.

Rinse, dry inside out, and expect the soles to wear through after a couple of seasons of rock. Glue small holes.