Growth on the waterline: any short term solution?

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jow

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Hi All,

my boat (always afloat on a swinging mooring) has a growth of green weed just above the waterline.
I had to scrub it off five weeks ago and it is back again.

Is there any short term solution to this?
I know I should raise the anti-fouling a bit, but this can't be done while the boat is afloat.
I was hoping for something like a paste or 'wonderstuff' to apply and do the painting over the winter.

Any ideas?

Thanks,
jow
 
I have the same problem and I have already lifted the waterline before. I find if you seal the gel coat with a sealer at the beginning of the season, it cuts down the amount of weed by quite a bit.
 
I havn t perfected Magic Paste underwater applied antifouling yet...!!!! However to prevent this in future I would suggest you apply up to 3 times more antifoul around the waterline,the rudder and Keel. There is much faster erosion in these areas so a standard coating gets eroded faster.
 
No short term solution but when you do raise waterline then be generous - I would suggest at least 2" minimum. Mine is about 6-8" above the waterline(it was like that when I got the boat and I just followed) which is probably a bit high but I never get any weed growth.
 
I use International bottop on a band 8cm wide and scrub from the dinghy when it looks iffy. Lifespan seems 3 seasons or so.
 
White Scotch pads and elbow grease.

Using polish to make the hull slipperier to stop the green sticking to the roughness of the gelcoat ...

I have a fore-and-aft mooring (not swinging) and it helps to point the bows into the prevailing wind/wakes that come through a gap in a line of pontoons beside Forethought - the water 'slops' less on the bow than the flatter hull at the transom, greenery still often spreads above the boot-topping.Forethought has a 10cm wide band of Trilux above the waterline and that is barely enough..
 
I would caution against the idea of using 3 times as much a/f on the waterline. What you will get after a few years is a huge build up of a/f which has to be scraped off. My own philosophy has been for many years minimum one coat a/f and lots of in water scrubbing. This means at the end of the season there is not much a/f left to scrape off.
(my circumstances are a bit easier than UK in that water is warm and I swim around under the boat almost every day. so scrubbing is no prob.) olewill
 
Hi,

thanks for the tips....

It seems there is no solution for this while the boat is afloat, beside scrubbing. /forums/images/graemlins/frown.gif
I use the waterbased international micron optima as a antifouling.
Therefore I can't paint the boat inbetween tides, because this stuff needs to dry for at least 1 day before immersion.

I am extremely happy with the paint, because at the end of the season a powerwash is enough to remove it completely and therefore no built up of coats ever again.

I will raise the waterline for next year, no doubt.

regards,
jow
 
Early days yet but a few weeks back I invented a brilliant solution to this problem (says he modestly).

I have tied a length of rough polyprop line, Nelson I think it's called, bow to stern both sides. It floats.

In a gentle popple it bobs up and down discouraging the green waterline stuff. In a blow when the boat thrashes from side to side the line gets dragged under on each oscillation and it's gradually rubbing off the half-season's growth below the waterline.

I don't suppose it'll get the barnacles off but it might discourage them!
 
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