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

What a pong! Funny smells on board your boat can be dangerous.

Two seasons ago I thought my holding tank was leaking. Up forward, where it lives, a distinct pong of rotten eggs was starting to pervade, so it was up with the boards for a look. All was dry underneath the wretched thing. We followed the pipes all the way, but found no serious trouble there either. We blitzed it with eco-disinfectant and stopped using it, but the smell still came and went periodically.

It was only last winter that I discovered that the big battery for the windlass and bow thruster that lives under the same bunk was breaking down. We got it out just in time, replaced it with the one you see here and
the smell departed overnight.

An accumulator that has reached this stage is not only a nuisance, it is dangerous.