How to Lower the Mainsail

Back to Basics Sailing Tips

Here is how to safely lower the mainsail on a Lagoon and similar catamarans.  We walk you though what you need to do, from heading into wind and securing the boom, to releasing the halyard and lowering the sail.

This demonstration was done on the Lagoon 42 and is intended to give you confidence in your catamaran handling ability.

Lagoon Catamaran Lowering the Mainsail

How to Prepare

00m 40s

  • Head into the wind
  • Furl the jib 
  • Put engines in tick over forward and place on autopilot. 

Lowering the Mainsail

01m 07s

Main halyard – This is attached to the top of the sail (the top, triangle part of the sail) and this pulls the sail all the way up to the top of the mast.  In order to get the sail down, we are letting this go, allowing the line to drop the sail.

Run the line through your fingers once just to make sure that there aren’t any kinks or knots in the line that will get caught in the jammer when it’s running out, which can make a smooth operation a little bit awkward.

Lagoon Catamaran Lowering the Mainsail
Lagoon Catamaran Lowering the Mainsail

Mainsheet – pull in all the slack to avoid the boom swinging around.

Topping lift (or boom lift) – a line which runs from the top of the mast to the back of the boom.  Make sure that this line is relatively tight but not too tight – and make sure that the jammer is closed.

Undo the jammer (or the clutch) with the main halyard in it – load the halyard onto the winch, take in some line, relieving the tension from the clutch / jammer, then open the clutch.

Ease main halyard slowly – undo a wrap from the top of the winch and hold while you ease out the halyard. When it gets a little lower and there’s less weight in the sail you can take another turn off the winch so there is less friction allowing it to fall down a little bit easier.

Keep looking up to see that the sail is coming down, and that it’s all falling into the boom bag.

Pack away the sail in the boom bag but do not zip up (if it is safe to do so). We always advise keeping the boom bag open so it is available if you need it. 

Lagoon Catamaran Lowering the Mainsail