Catamarans can be a bit frisky at anchor, but multihull expert Nigel Irens has some tips to make anchoring and mooring safer and more comfortable

YW Cat Sailing Techniques logoAmong the plus sides of cruising in a catamaran is that inherent shallow draught offers access to plenty of sheltered and attractive anchorages that are not available to deeper-keeled yachts.

The general game plan in anchoring on a cat under power is much as it is on a monohull – approach the spot where you intend to drop the anchor from dead downwind and signal to the foredeck when you are ready for it to be dropped.

The only snag is the catamaran’s stubborn desire not to remain in a stable condition head-to-wind in anything but the lightest breeze. It’s just as well, then, that the twin engines allow you to hold station and heading reasonably well, provided you’re firm with the controls and act with as much deliberation as you can muster.

It obviously helps if you can avoid hanging around too long in limbo with no way on – which invites that headwind to take control of the boat.

Keeping your position

Once the anchor is on the bottom you can drop back downwind – once again playing the engine controls to help the boat stay head to wind until the point where you have snubbed the anchor in.

If you’re operating in waters that are free from tidal movement or other currents you might expect to lie head to wind like the other boats around you, but there’s another snag that needs to be addressed before you can feel relaxed about this. The problem is related to the above-mentioned reluctance of a catamaran to lie head to wind, although with any luck your boat will already be fitted with a solution to this one.

What happens is that the boat starts to range around the anchor. This process begins as the bow falls off to one side or the other and the boat starts to ‘sail’ forward – say at about 45° to the wind axis. Eventually the bow will be forced to come head to wind because the direction of travel can only be a radius around the anchor.

Eventually the boat slows down and comes to wind, but because the anchor rode is still pulling the bow to one side the boat tacks through the eye of the wind and sets off with renewed vigour on the other tack.

It’s not hard to imagine that this cyclic pattern can repeat itself until the boat is careering about, taking up much too much space in the anchorage and generally winding up the neighbours. Viewed from above the physics of this phenomenon is not unlike that which makes a flag flap.

The bridle takes the load and the anchor chain to the boat is now slack. Note recovery line

The bridle takes the load and the anchor chain to the boat is now slack. Note recovery line

To solve the problem the anchor rode needs to be attached to a bridle rather than directly to the bow roller. This involves attaching one end of a rope to each bow and the middle of the resulting span to the anchor chain or warp. As the bow of the boat falls off the wind axis the tendency is for the rope on the lee bow to take the load as the windward one goes slack.

This asymmetric load will be far more effective in putting the boat back head to wind before it has had time to build up any speed than a single rode to the centreline.

Anchor sequence

You can experiment with the length of the bridle, but something approaching an equilateral triangle (as viewed from above) seems to work pretty well, although the boat you’re sailing probably has the bridle already set up correctly and ready to use.

Clear hand signals are also required when raising the anchor to help the helmsman reduce load on the windlass

Clear hand signals are also required when raising the anchor to help the helmsman reduce load on the windlass


So the sequence of events in anchoring is roughly as follows:

  1. Pick the best looking spot to anchor
  2. Approach the chosen spot from downwind and give the crew the go-ahead to drop the anchor when you’re in position.
  3. Move astern downwind as the crew pay out the anchor rode and snub the anchor in.
  4. Set the bridle and slacken the anchor rode until the load is taken up by the bridle.
  5. If the boat won’t settle at her anchor for some reason – fickle winds, some unwanted counter current or whatever – you may have to think about laying a second anchor.

This is best done from the tender and although the learning curve might be quite steep, a bit of trial and error could leave you better placed for the day you need to ride out heavy weather from a known direction.

The second anchor should be set so that the angle between the first and second anchor chain is between 90° and 60°.

Picking up a mooring

If you are picking up a mooring rather than anchoring, visibility – or the lack of it – might be a problem, so the old tactic of getting a crewmember to hold the boathook aloft from the forward end of the boat and point it at the buoy is as good a way as any of telling the helmsman what’s happening.

If the buoy you’re aiming to pick up has no rope or chain leader attached to it then it might be almost impossible to get a temporary line through the ring without launching the tender – especially if your freeboard is high. If so there’s a cheeky work-around involving offering the boat up to the mooring stern first.

Using a boat hook to help guide the helmsman to the buoy that you want to pick up. Don’t worry about looking like a whaler about to launch a harpoon!

Using a boat hook to help guide the helmsman to the buoy that you want to pick up. Don’t worry about looking like a whaler about to launch a harpoon!

For a start the helmsman should have both a good view of the buoy and the ability to communicate with the line handler. Once a line has been attached, the helmsman should be able to spin the boat round easily enough so the line handler can to bring a slack mooring line round to the bow as the boat turns – but not so slack as to risk it getting sucked in by the propeller, which could be embarrassing at best and dangerous at worst.

Mooring sequence

A recap on the procedure would read something like this:

  1. Find the buoy you have been allotted – or choose a suitable one if you haven’t had any specific instructions.
  2. Bring the boat up to it from downwind and get the crew to bring up the leader with the boat hook, get a temporary line through the eye and secure the free end on a cleat or any other strong point that comes to hand.
  3. That’s it – you’re safe! It just remains to set the bridle as above and you’re done.

Anchoring or picking up a mooring under sail is more difficult than would be the case in a monohull. This results from that old problem about catamarans being more skittish than monohulls, having more windage above the water and less hull below it.

That is not to say that it couldn’t be attempted when an anchorage is spacious enough and not overcrowded. On the contrary, taking on such challenges in the right conditions helps build confidence and develop the skills necessary to anticipate the way the boat will behave in different circumstances.

Ultimately much of the pleasure that sailing has to offer involves mastering new skills and developing prowess in handing whatever boat you happen to be sailing.

Inevitably doing so involves taking on challenges that will get your adrenalin popping from time to time – as it is meant to do. It was ever thus!

Do’s and don’ts

  • DO spend some time practising holding your catamaran head to wind under power.
  • DO snub the anchor in properly so that you can feel the boat being tugged forward when you put the engine back in neutral.
  • DO make sure your crew are properly briefed about their role in making anchoring and mooring a pleasure.
  • DON’T forget to make sure they know they should delay paying out more chain after the anchor has hit the bottom until the boat is visibly moving astern. This avoids the risk of chain piling up on top of the anchor and perhaps fouling the flukes.
  • DON’T drop an anchor if there really isn’t enough space. A catamaran needs more space than other boats because it is big and often a bit frisky at anchor.
  • DON’T give up too easily – you have an ace card to play in that you draw less than the average monohull so can probably find some clear water that’s no use to them! In tidal waters you can even dry out and have a very peaceful night.


Our eight-part Catamaran Sailing Skills series by Nigel Irens, in association with Pantaenius, is essential reading for anyone considering a catamaran after being more familiar with handling a monohull.

Part 4: Cruising upwind under sail – potentially a cat’s weakest point of sail

AY7Q3617Series author: Nigel Irens

One name stands out when you think of multihull design: the British designer Nigel Irens.

His career began when he studied Boatyard Management at what is now Solent University before opening a sailing school in Bristol and later moving to a multihull yard. He and a friend, Mark Pridie, won their class in the 1978 Round Britain race in a salvaged Dick Newick-designed 31-footer. Later, in 1985, he won the Round Britain Race with Tony Bullimore with whom he was jointly awarded Yachtsman of the Year.

His first major design success came in 1984 when his 80ft LOA catamaran Formule Tag set a new 24-hour run, clocking 518 miles. During the 1990s it was his designs that were dominant on the racecourse: Mike Birch’s Fujicolour, Philippe Poupon’s Fleury Michon VIII, Tony Bullimore’s Apricot. Most famous of all was Ellen MacArthur’s 75ft trimaran B&Q, which beat the solo round the world record in 2005.

His designs have included cruising and racing boats, powerboats and monohulls, but it is multis he is best known for.

See the full series here

A special thanks to The Moorings, which supplied a 4800 cat out of their base in Tortola, BVI.