Yacht Forum UK

I think I get the idea behind this, but if wrong, please let me know
As far as I understand it's to hold the boom out and stop it swinging from one side to the other uncontrolled, which could take a head off ?
If so, how do I manage it ?
Sorry for the dumb question, managed to figure out quite a bit but this one's still confusing me, and when I mentioned it to the other yachties up here they just laughed and said they've never heard of it
In which case, do I even need one ?

Dave,

The idea is to prevent the boom 'whanging' across the cockpit with speed and violence, in the event of an uncontrolled gybe - which most often happens at night, and /or in strong breeze, and lumpy seas - while running downwind, with the helmsman tired and switched-off. It kills......

At at the very least, it splits tired old mainsails - and cracks open tired old skulls. Take it seriously.

A 'preventer' is no substitute for awareness and switched-on boat-handling but we all get tired. It holds the eased-out boom forward, unable to gybe across, so the risk to rig and crew is contained. Conversely, it is also a hazard if the boat gybes 'uncontrolled', then broaches, then is knocked-down by a following sea. So using a 'preventer' is a balanced decision.

One method is clipping a 'handy billy' purchase between the toerail and the mid-part of the boom 'above and abaft' that point, so that the restraint leads forward and down. That usually requires a crewman to go forward on the lee side to remove it, prior to a controlled gybe - which is slow and sometimes a touch hazardous. Another way is to lead a line from about the same mid-point on the boom, forward to a turning block near the bows, then back to a jammer/cleat on the coachroof ( accessible to the cockpit). This permits the 'preventer' to be both eased and hauled from the safety of the cockpit. A pair of them - one each side - is commonplace on a lengthy downwind leg, such as Gran Canaria to Barbados, or Lowestoft to Ostend.....

I'd recommend to you having the latter available.

Brilliant, thanks BB, I'll have a go at that this week and see how it goes after that