Open-cell wetsuit

The wetsuit keeps you warm enough to stay still. A spearo spends most of the dive motionless on the bottom or at the surface, and a cold diver shivers, burns oxygen, shortens every breath-hold and gives up early. On the Moroccan Atlantic the water is 15 to 20 °C most of the year, and even the Mediterranean drops to 14 °C in winter: without a proper suit the season is two months long.

It also protects you from rock, urchins, jellyfish and the sun, and its buoyancy is what the weight belt is there to cancel.

A spearfishing suit is not a surfing or scuba suit. It is two pieces: high-waisted trousers and a jacket with an attached hood and a beaver-tail that clips between the legs. There is no zip. The inside is open-cell neoprene, raw foam that sticks to the skin and lets almost no water in, which is why it is far warmer than a lined suit of the same thickness, and why it has to be put on wet with soapy water.

Thickness for this coast:

• 5 mm for the Atlantic most of the year, and for anyone who feels the cold.
• 3 mm for the Mediterranean in summer and the Atlantic south in late summer; not enough for a long winter session anywhere.
• 7 mm for winter on the Atlantic north, if you dive it.

Many divers own a 5 and a 3. If you own one, own the 5.

The outside can be smooth-skin or a nylon lining. Lined outside is tougher on rock and easier to put on; smooth-skin is warmer in wind at the surface and more fragile. Camouflage patterns are for the fish's benefit and are a matter of taste; in the surge over rock a broken pattern does help.

A chest loading pad, a thicker patch on the jacket, is a small thing that saves your sternum when loading a gun.

A suit that fits is snug everywhere with no folds and no air pockets: at the armpits, behind the knees, at the small of the back. Folds fill with water and pump cold in with every movement. Off-the-shelf suits fit most people well enough; a tall, short, broad or slim diver is better served by a made-to-measure suit, which costs little more and lasts longer because it is not being stretched where it does not fit. Put it on with a bucket of water and hair conditioner or a purpose lubricant, never dry.

Rinse in fresh water after every dive, inside and out, and dry it inside out in the shade, then right way out. Never leave it in the sun, in a hot car, or folded wet in a bag. Hang it by the waist or over a wide bar, not on a wire hanger, which cuts the shoulders. Open-cell neoprene tears if pulled on dry; put it on with lubricant every time. A small tear is repaired with neoprene glue in five minutes and left to cure overnight; a tear left alone becomes a hole.