Practical advice for all sailors. Tom Cunliffe has sailed tens of thousands of miles all over the world and has been a Yachtmaster Examiner since 1978

Back to front is right for ventilation

Ventilation is critical to the life expectancy of a wooden boat, particularly when left on a mooring. No GRP yacht ever sank through mildew, but we still like our vessels to keep nice and fresh. It’s worth bearing in mind, therefore, that a well-designed yacht vents from aft to forward, not the other way round as you might expect.

What this means specifically on your boat is anyone’s guess, but it always helps to know what’s going on. On mine, this ventilator, deliberately turned forward ‘against the grain’ to ram some dry air into the shower compartment, will be swivelled to face aft when I dinghy ashore.

Not only will it then be less vulnerable to rain ingress, the low pressure on what is the downwind side for most of the time will suck stale air out of the boat, as fresh pours in from ventilators aft.B