Bottom Slime - Does it come off after a sail

[LONG_KEELER]

I don't think it does. Any views ?

 

[Chiara’s slave]

I don't think it does. Any views ?

Not at ordinary sailing speeds. It comes off my RIB if you get to 30kn or so. It’s why, in the XOD fleet, everyone leans over the side with a brush, or even snorkels at low tide.

 

[johnalison]

Not a hope. The thing that puzzles me is that when I paint the bottom it ends up just slightly rough, and a bit slime over it is smooth, so why doen't my boat go faster instead of slower? I suppose it is like a golf ball, but it's very annoying.

 

[Chiara’s slave]

Not a hope. The thing that puzzles me is that when I paint the bottom it ends up just slightly rough, and a bit slime over it is smooth, so why doen't my boat go faster instead of slower? I suppose it is like a golf ball, but it's very annoying.

The answer is that whilst you feel it as smooth slime, it’s actually fine hairs, and can be quite long. Like trying to sail with fur. Cats don't like swimming for the same reason maybe.?

 

[Concerto]

You may lose some if you sail in rough weather either cutting into waves or travelling very fast on a broad reach. Another alternative is to go into fresh water as this kills salt water weed. Finally and probably the best to reduce the slime is a quick scrub round the waterline with a long handled brush.

Realisically, the only way to get a clean underwater profile is a proper scrub, either drying out or being lifted.

 

[William_H]

Realisically, the only way to get a clean underwater profile is a proper scrub, either drying out or being lifted.

Or best just get in the water with mask and snorkel and scrub away ol'will OK wetsuit if you are a woosss

 

[Iliade]

Or sail close inshore near to any of our major headlands; The pot ropes will scrape it off nicely!

Or get one of these:
Scrubbis Hull Cleaning Set - Online Storehttps://apollomarine.co.uk › ... › Cleaning.
Tried & Tested: Scrubbis Hull Cleaning System - Yachting Monthly

 

[Daydream believer]

Or best just get in the water with mask and snorkel and scrub away ol'will OK wetsuit if you are a woosss

Or fix a scrubbing brush to one half of a sailboard boom. ( It is curved so follows the hull shape). Fit a 1 litre empty lemonade bottle under it to make it float against the hull. Then stand on a pontoon & scrub it off whilst chatting to your mates.

 

[oldgit]

Nope. No chance.
Not even after a decent run a 20 knots.
Needed a very powerful jet wash to efficiently and properly shift.
One of those toy B&Q jobbies would have taken ages.
Remarkably little growth on the bottom this year, a handful of small barneycules and a impressive thick layer of slime. No trace of long weed or that hard to shift thin layer of coral stuff.

 

[LONG_KEELER]

A powerboating neighbour near me says it definitely doesn't . Even without weed ,shell and general hairyness he cant get it up on the plane when there is slime. He seems to scrub with a device most weeks.

 

[wombat88]

Some have been known to take a garden hoe to adjacent underwater marina floats and posts etc and scrape them clean.

Whether the removal of local encrustations of stuff has any effect or not is unknown.

 

[johnalison]

A powerboating neighbour near me says it definitely doesn't . Even without weed ,shell and general hairyness he cant get it up on the plane when there is slime. He seems to scrub with a device most weeks.

According to one of our engineers that is a problem with modern engines. In the old days a bit more welly would have done the trick but modern engines have to prevent pollution and will detect the additional load and refuse to give more power.

 

[Leighb]

When I was racing a keelboat, it was quite obvious that if you wished to win, you had to scrub before every race. I used to do it from on board, heeling the boat over by hoisting the dinghy with a tackle from the end of the boom and then leaning out over the side with a long brush. Seemed to work pretty well.
Just had to watch out for passing boats dragging a lot of wash, hastily loosening the tackle if one was spotted!
Even 2 weeks of slime growth has a big effect on hull drag at the relatively low speeds of a 20' boat.

 

[Concerto]

Or best just get in the water with mask and snorkel and scrub away ol'will OK wetsuit if you are a woosss

Current water temperature is about 8 degrees centigrade. That is colder than your cold water coming out of your home tap. So, rather you than me in the water to scrub.

 

[Daydream believer]

Current water temperature is about 8 degrees centigrade. That is colder than your cold water coming out of your home tap. So, rather you than me in the water to scrub.

A few dinghy sailors at our club this week & there was an open meeting. A few ended up in the drink & apart from their results, they did not seem to let it worry them. I shall be working on the water all this week & next & have to admit, that whilst I felt the same in my youth, I certainly do not want to try it now.

 

[Alfie168]

There is a moment of realisation when you go for a sail in my mates lift keeler that the real reason he wants you on board is to be at the other end of his "push me pull you" hull cleaning apparatus.....nuff said ?

 

[Laminar Flow]

We have found that even a thin layer of slime costs about 10-12% in speed.
We alternate between fresh and salt water, dry out fairly frequently, at which point the bottom gets a scrub. With that kind of treatment, a decent ablative type of antifoul lasts us 3-4 years. The last batch of paint we got in Holland was growing a beard after just 2 months, in spite of the boat being near constantly moved.
Fortunately, the drying grid at St. Malo, which collects the run-off and has a super powerful washer, only costs 20 Euro to use.

 

[coveman]

I don't race now but when I did we used to have a length of old course carpet about 2ft wide with holes both ends to which were attached a length of rope at each end. Two crew each standing on each side of the boat could then pull the carpet back and forward under the hull. It worked well but you couldn't do the area each side of the keel. It might not be perfect but avoids hypothermia!

 

[thinwater]

Look at the Davis Scrubis and related products. I thought it couldn't work, but with the Groovey head, I'll be darned if it doesn't work on slime.

The trick is that the floating head does the work. Push it down, and it scrubs on the upstroke. Not as good as diving, and not for hard growth, but good for touch ups on light soft growth. I used it in the shoulder seasons, when there is some growth but it is too cold for swimming.

Scrubis

 

[KeelsonGraham]

Dust on an airliner’s wing before flight will still be there after it’s flown. It’s to do with the boundary layer conditions.

Likewise on a boat, in the boundary layer water flows past the hull far slower than the speed of the boat. In fact, in the boundary layer closest to the hull, there’s no relative flow at all.