Simon Johnson asks: “I’m planning to sail my boat Zeno back to Britain from Corfu next spring and as the Volvo Penta 130S saildrive seal was due to be changed in 2020 I decided to fly out to Corfu to change it rather than wait until the boat is home.

“This might seem a little excessive because although the Volvo manual states the seal should be changed every seven years, many people talk of changing the seals much less frequently, perhaps every 15 or 20 years. Indeed when I last changed the seal in 2014 I found that the old one still looked like new.

“But when I disassembled the saildrive recently I was shocked to find that the seal was split nearly through in several places.

Obvious signs of cracking on this saildrive seal which has been out of the water in a hot climate during lockdown

“I don’t know if the problem was caused by the boat being ashore throughout the pandemic in the 42°C heat of the Corfu summers but whatever the cause I’d like other boat owners to take the importance of the seven year seal change seriously.

“If the seal were to fail offshore (probably in heavy weather when more load is placed on it) the boat would almost certainly sink as stopping the leak would be difficult if not impossible.

“I sent photos to Volvo Penta who replied that they believed the seal damage may have been caused when the boat was lifted, with strops forcing the saildrive leg out of position and causing the splits.

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“I find it this hard to believe as I’ve been present at every lift of the boat except for one at which a trusted professional yacht maintainer was present on my behalf.

“I have lift point marks on the side of the hull and the travel-lift crew have always lifted the boat with plenty of care. That said, I can’t absolutely guarantee that this isn’t the cause.

“I wonder how many other owners put their boat ashore in the autumn of 2019 and because of the pandemic are only now thinking of relaunching? I’d certainly advise them to check their seals.”

Volvo saildrive seal replacement – the expert’s view

Stu Davies replies: “Simon is quite right, the seals anecdotally last for a lot longer than the often quoted seven years.

“Covid is causing lots of owners to leave their boats for long periods of time unattended on the hard, and Greece for one is a country with extreme temperatures.

“My initial reaction when seeing the photos was UV damage, but having talked to the owner since he said the cracked side was on the bottom which is covered by the hull fairing and not exposed to sunlight.

“If the seal had been damaged during a lift I’d have expected to also see signs of damage on the rear engine mount as well, but apparently there weren’t any.

“So Simon’s theory that the time on the hard – two years, plus temperatures of up to 42°C – had caused the ‘rubber’ to deteriorate may well be correct.

“When the boat is afloat, the hull and appendages are kept cool by seawater and are likely to have a much longer life. Luckily he decided to change the seal before he sailed home.

“An important lesson learned in these Covid times is that if your boat has been left on the hard in extreme temperatures for an extended time, check your saildrive seals very carefully before launching.

“Of course, the only real way to thoroughly check the seal is to remove the saildrive leg – at which point you may as well renew the seal anyway.

“It’s also probably worthwhile checking any ‘rubber’ cutless bearings and prop shaft seals if you have them.”

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