Start with the crew, not the kit

Short-handed sailing — usually two of you aboard, sometimes only one awake — changes the arithmetic of safety. Every problem lands on one pair of hands. Add a catamaran's wide beam, its quick, jerky motion in a chop and the long walk from the cockpit to the bow, and you have a boat where a moment's carelessness gets punished quickly. The best piece of safety equipment you own is a rested crew who already knows what happens when things go wrong.

Before you slip the lines, sit down together and talk it through: the route, the forecast, the bail-out harbours, who does what if someone goes over the side or the wind pipes up. Ten minutes on a pontoon is worth more than any gadget you can buy.

Lifejackets and harnesses that actually get worn

Buy jackets you will genuinely put on, because the best one is the one that is on your back. For coastal cruising around the UK a 150N automatic jacket is the sensible minimum; if you sail through the winter, cross the Channel or sail at night, go for 275N with a sprayhood — it keeps your airway clear when a wave breaks over you.

• A crutch strap is not optional. Catamarans throw you about; a jacket that rides up over your head is worse than useless.
• Check the cylinder and the firing head before every trip, and have each jacket serviced annually. Inflate one by mouth once a season so you know how it feels.
• Fit a light, a whistle and a personal knife to the jacket, and keep them there.
• An integrated harness with a strong chest point, worn over your layers but under your outer shell, so the tether stays clear.

Wear the jacket in the dinghy too. Most people who drown in UK waters are not offshore sailors in a gale — they are people in a tender in a flat calm.

Jacklines, tethers and staying on board

On a multihull the safe zone is the cockpit, and the whole point of a tether is to make leaving it a deliberate act rather than an accident. Run jacklines from the aft end of each hull forward to a strong point at the mast or the bow cleats, keeping them outboard of the coachroof so they never become a trip hazard. Flat webbing is better than rope: it does not roll under a boot.

• Tension the jacklines properly. Slack line means a slack fall, and a slack fall means you go over the rail.
• Use a double tether — long leg and short leg — so you are clipped on at all times, including when you move past the shrouds.
• The trampoline is a no-go area single-handed at sea. It is a large hole covered in netting, and there is nothing to clip to.
• At night, make a rule: nobody leaves the cockpit without waking the other. On a catamaran you may not hear a fall from the other hull.

PLBs, radios and being found

A man overboard who is not found is a fatality, and on a catamaran you may lose sight of someone quickly beneath the bridge deck. Carry a personal locator beacon on your body, not in a grab bag — a 406 MHz beacon with an internal GPS, registered free with the coastguard so they know who you are and who to ring. A personal AIS beacon is a useful addition: it puts a target on your own plotter and on nearby ships.

Fit a DSC VHF at the chart table and carry a waterproof handheld in a pouch on your lifejacket, with the MMSI programmed in and the set tested before you leave. Know how to send a distress alert, and practise saying the words aloud. Keep a mobile phone in a waterproof case as a backup, never as a plan.

Briefings and drills before you leave harbour

Agree the routine before you need it. Walk the boat together and point at things: the liferaft or grab bag, the flares or electronic alternatives, the fire extinguishers, the gas shut-off, the seacocks, the first aid kit, the bolt cutters for the rigging. Show your crew how to start the engine, how to stop it, how to drop the sails and how to call for help on the radio.

Then run a man overboard drill in flat water. Press the MOB button on the plotter, throw a danbuoy or a float with a light, kill the boat's speed, drop the sails if you can, and motor back on the reciprocal course, approaching from downwind so you do not run over the casualty. Rig your recovery system before you need it — a four-to-one purchase from the boom, a lifting strop, and a boarding ladder at the transom. On a catamaran the boom is high above a stable platform, which makes it an excellent crane.

Practise with a fender on a calm afternoon, then again in a bit of a chop. Do it monthly in season. The drill you have rehearsed is the one you will actually manage at two in the morning, cold, tired and frightened — and that is precisely when it matters.