To antifoul or not?

[Majic]

Our boat is now out of the water for the season. Thanks to Brexit we only get 3months on her each year.
The hull was last antifouled in 2018. When hauled out there is some growth but this is quickly removed by jet washing.
This leaves the hull looking a bit patchy, with white gell coat showing through the remains of the old antifoul, but I'm loathe to spend a couple of hundred euros on poisonous paint that is designed to wash off by the end of the year.
So is there any benefit to antifouling for me, other than making the boat look good in the yard?

 

[ChromeDome]

When the AF disappears is a self-polishing type. The water is polishing the 'dead' paint away as you go, to keep the surface active. If it is all gone at the end of the season you applied the right amount for your use and waters.

No one gives a toss about the looks when on the hard between seasons and the idea is to apply new just before the next season (AF's have a specified maximum time between application and launch).

There are several AF types besides self-polishing so while the boat is on the hard you can investigate and decide if you want to change (and check the conditions for doing so).

Edit: The patches you see should be primer under the AF - not Gelcoat. New AF can be found both expensive and less so,

 

[LadyInBed]

Thanks to Brexit we only get 3months on her each year.

But how long is the boat in the water for?
If it's only for the 3 months plus a week or so, then try it without AF'ing. If it spends best part of the year in the water waiting for you to turn up then you will need AF unless you can put up with just plodding along at half speed if there late in the season.

 

[William_H]

I sympathise with comments re the look of the boat with patchy anti foul. My boat sits all winter on trailer at my house. The boat overlooks a public car park and is a bit higher than the car park. Such that all winter the most obvious part is the patchy a/f and it makes the boat look really tatty. I did slap some a/f on top cover the patches of missing paint this year just to make it look loved. It does not seem to matter if you apply a/f months before relaunch.
I would suggest if you have survived for 4 years without repainting a/f then continue as is. Perhaps a bit of enamel paint right colour to make it look better. ol'will

 

[Chiara’s slave]

I sympathise with comments re the look of the boat with patchy anti foul. My boat sits all winter on trailer at my house. The boat overlooks a public car park and is a bit higher than the car park. Such that all winter the most obvious part is the patchy a/f and it makes the boat look really tatty. I did slap some a/f on top cover the patches of missing paint this year just to make it look loved. It does not seem to matter if you apply a/f months before relaunch.
I would suggest if you have survived for 4 years without repainting a/f then continue as is. Perhaps a bit of enamel paint right colour to make it look better. ol'will

There’s a school of thought that believes car paint to be more poisonous than modern antifoul.

 

[Stemar]

I gave up on antifoul because, on a drying mooring, it just didn't work, but I had a cheap scrubbing grid with jet wash handy. I'm guessing you're in the Med, so you won't have tidal grids, but for three months in the water, I'd certainly give it a try without and see what happens.

 

[vyv_cox]

My first boat was 11 years old when I bought it and had never been antifouled. It was kept alongside a drying jetty at Fleetwood, where the previous owner would brush down the hull once per month at low tide.

 

[Neeves]

We need to apply new AF but the weather will not be very conducive till late October, I've become a wimp. We are going to beach on the 12th September just for the day, the tides are accomodating, simply to wipe down as we cannot risk allowing the fouling to grow unattended for a further month. Once fouling starts it grows exponentially and the impact on performance is simply too noticeable.

Jonathan

 

[RJJ]

I think OP question was: accepting that it will look tatty on land, accepting that performance will suffer from heavy fouling in month 3 of 3, is there any harm from just leaving it to gelcoat for 3 months in the water?

My best understanding is no - the gelcoat itself should not be harmed by accumulating growth BUT I suspect the jet wash on haulout may be less effective than we are all used to. If you change your mind and revert to antifouling after two summers without, I would expect a reasonable amount of work/money to clean back to gelcoat before re-priming and painting. But if it was three summers, you've probably saved enough work/money to compensate.

 

[Mudisox]

Water is warm at the moment encouraging growth.

 

[Neeves]

Some growth, shells, are quite tenacious and so much so that a commercial power wash does not remove everything. If you did it yourself you might be a bit more rigorous but most employees don't have the same dedication as the owner. Once the power wash is complete and you look the yacht over you see the places that were not cleaned properly and YOU may damage the gel coat trying to remove the last of the shells. Gelcoat does not resist an enthusiastically applied sharp scraper. The fouling may not damage the gelcoat you might.

If you are leaving your yacht in the water with old or patchy AF expect it to foul. If left in warm nutritious water expect it to foul quickly and with increasing speed of fouling and if you fancy a sail - with increasingly decreased performance. If you are moored next to a heavily fouled yacht - you will suffer from increased fouling.

If its sitting on the hard - who cares what it looks like (but wash the fouling off as soon as she is lifted).

Jonathan

 

[Chiara’s slave]

Most yards will wash boats at lift out, or the yard will stink to high heaven.