Hi everyone,

My Yamaha MS-24 is on a mooring and I have excessive algae growth on the hull. I just had the boat out 1 month ago, did the antifoul, did the prop, and cleaned the hull with hull cleaner.

It has been 1 month since the boat is back in the water, also did two trips in the meantime, and the algae is back. I took the picture a month ago when we got the boat out, but the hull looks pretty much the same again.

I did not wax the hull after cleaning, was that the problem?

Any tips are welcome ??

thanks in advance,
Yamaha24ft

Not much that you can do other than scrub.
That is muck that floats on the surface of the water and clings to anything.
Try to rig up a stiff broom (curved or something) that does the job reasonably easy and hope that cooler water will bring a reduction.
The good point is that you can't see it when you are on the boat.


Prop looks like it needs a good shave in that photo.
Try to at least keep it clean.
gary

Increase the height of the antifoul. It may look OK in still water but with a fast tide or passing boat wash what you have is what you end up with.

RE; Increase the height of the antifoul.

Or dark brown boot-topping.

+ 50mm Antifoul,then dark boot topping .

Bestest clean with Sabco Telescopic Caravan/Truck Brush from Mitre 10. All Alloy,and goes out to 6ft,so I can reach 4ft keel,and can lever off dinghy gunwhale to increase pressure. Softish bristles,with solid head for shell/growth. Had one for 2 years,with regular use - just rinse and repeat !

Anything better than dip -diving,and then swimming in the debris !

Mason

Look very carefully, you will see a 3 inch white line of different colour at the boot top.
It is white antifoul.
Rosie lives at the front of the house at end of a casual so lots of grim.
So don't raise boot top and spoil then look just do the 3 inch stipe in white antifoul.

also works well if you live on a mooring with surge or ferry wash.

Lovely boat.
With the original photo I think it should be top booting, not boot topping.
Brown!

Cheers

Select to expand quote

Yamaha24ft said..
Hi everyone,

My Yamaha MS-24 is on a mooring and I have excessive algae growth on the hull. I just had the boat out 1 month ago, did the antifoul, did the prop, and cleaned the hull with hull cleaner.

It has been 1 month since the boat is back in the water, also did two trips in the meantime, and the algae is back. I took the picture a month ago when we got the boat out, but the hull looks pretty much the same again.

I did not wax the hull after cleaning, was that the problem?

Any tips are welcome ??

thanks in advance,
Yamaha24ft

I have similar thing on my boat ( anchor on Brisbane River ). Unfortunately it's elbow grease from time to time, but to help I use 2 things, grease and stain remove from Mr Whitworths and believe or not .......domestos. Get some on kitchen spunch and smear all over the green crap, wait I few minutes and just scrub. Any stain left i spray with stain remover and few minutes later scrub or not and splash /rinse with water.
My prop checked by diver some weeks ago and reported as clean. I used Tilux 33 with copper in it.
Last bottom paint about year ago .
At least once a week i start engine in gear ( reverse ) - ( anchor ).

As always, thank you everyone for the prompt reply. I might add another few mm of antifoul next time I get it out. For now I will go with hull cleaner again and scrub as recommended. It was just crazy how quickly it was back after I just had it out! Never had the algae back before this quickly, after just 1 month back in the water.

Also, thanks for comments on the prop. The photo was taken when I got it out last month, prop was cleaned sanded and painted before it went back in the water (I usually go with prop speed, but I tried just a bit of antifoul this time instead, to see if it makes a difference).

Prop speed = good for fast spinning props used regularly. Slow props seem to do well with hard antifoul. Not a light spray but a good slop on job works for me

Scrub with generic bleach with a squirt of washing up detergent as a wetting agent. Scrub with generic scouring pad (3M and Scotchbright are too aggressive and will scratch your gelcoat).
Wash down with oxalic acid for the stain. Raise the waterline antifoul. (No boot topping).
At least 5 thin coats of antifoul paint on your prop as you antifoul the bottom will see you through at least a year. Proposed is hellishly expensive and is best on props used regularly.
Oxalic acid will oxidise the gelcoat slightly so polishing after is recommended.