How to set a pre-rigged preventer
A preventer is essential to avoid an accidental jibe while downwind sailing
The no-hassle, simple, reliable preventer that is set in less than 60 seconds
To set a preventer the moment there is the slightest risk of a jibe is essential. Often, waves and weather prevents the crew to fancy setting it, which can be dangerous. Instead of having to attach a line at the end of the boom and lead it forward to a bow cleat can be a daunting experience and therefore it’s very handy to have the preventer pre-rigged on both sides.
The first part of the preventer (black line) is already led from the end of the boom on both sides and fixed to a cleat at the forward end of the boom close to the mast. It has a spliced eye in the Dyneema line so it can easily be prolonged when being used.
The pre-rigged first part of the preventer is already attached to the end of the boom and lead forward to a cleat on the boom. There are two of these black Dyneema lines on each side of the boom.
The black part of the preventer is attached to the end of the boom.
Some smart clips prevent it from clapping against the boom.
In order to prevent the line to clap against the boom, it is held in place by a 3-D printed plastic clip that may sailing colleague Martin Jarvis makes for fellow sailors.
The second part of the preventer (green line) is parked along a stanchion at the height of the mast. By this, the crew only needs to crawl or walk up to the mast and not all the way forward. Don’t forget to clip on if there are high waves!
The green part of the preventer is normally parted around a stanchion at the hight of the mast. There is one on each side of the boat.
The green part of the preventer is already led through a low-friction ring that is attached to the bow cleat by means of strong Dyneema line.
The preventer is lead through a low friction ring at the bow.
The green and black part of the preventer are then connected by means of a bowline knot through the eye of the black preventer.
The green part of the preventer connected to the black part by means of a bowline knot.
You can now control the preventer form the cockpit: stretch the green line which is held by means of a Spinlock clutch.
The low-friction ring facilitates that you can pull comfortably from the cockpit, but it is held by means of a strong Spinlock clutch.
Please note that a clam cleat is not strong enough to hold the extreme forces that occur during an accidental jibe (ask me: I know for sure!).
Warning: Do NOT use a block with a clam cleat like this. It will NOT survive a true accidental jibe in gale-force winds!
After you have pulled on the green preventer, it is then finally stretched by means of the main sheet so the boom is completely held in place and has no play.
See video here: