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Different marine growth rates on hulls, Sydney areas !

PostPosted: Sat Jan 18, 2014 8:40 am
by Topi
I dived under the Top Hat yesterday, we just bough it this week. I noted that the marine growth on it was totally different to what grows in the Georges River. It is easy to do a comparison as both vessels were antifouled within a month of each other abour 14 months ago. The Top Hat (near Manly) has no slime, it did have tube worm looking things, a orange lichen looking thing and some barnacles. The Botany Bay vessel has thick slime (usually does) and barnacles.

To me it appears that the water clarity of the Manly mooring equates to no slime. The BB moored vessel gets thick slime probably from the murky water. The keel can sometimes touch the bottom on a very low tide, yet I have in 10 years never seen the bottom of the bay there.

One other factor that may influence the growth, is the antifoul. I use Altex #5 ablative, generously applied (min 3 coats, more in strategic spots). The Top Hat appears to have a hard antifoul as when I scraped it nothing came off into the water, unike the ablative versions.

If the just the water quality is the reason for the difference, then paying a bit more to be in the seaward bays of Sydney harbour is probably worth it with less frequent antifoul jobs, no slime and clear water to dive under the boat for a regular clean. Oh, the chap I bought the Top Hat from said he had not cleaned the hull since the last antifoul job.

Re: Different marine growth rates on hulls, Sydney areas !

PostPosted: Sat Jan 18, 2014 2:13 pm
by Topi
This morning I had to go out to the boat & I ran into a shipwright who has his own boat on Burraneer Bay. We got into a discussion on the antifoul issue & he said that the slime is characteristic of Botany Bay and furthur up the other harbours. In the more seaward mooring areas the tube worm takes over from the slime.

Re: Different marine growth rates on hulls, Sydney areas !

PostPosted: Sat Jan 18, 2014 3:23 pm
by Troppo
I guess then that different types of antifouls would work better in some places than others.

Re: Different marine growth rates on hulls, Sydney areas !

PostPosted: Sat Jan 18, 2014 4:48 pm
by Topi
You might have it in a nutshell. That might also explain why different people "grow attached" to a brand of antifoul. To take a reccomendation on an antifoul first you need to match the ecology of the water you plan to have the vessel in. Because someone has a good paint for Manly does not mean it will work in Botany Bay.

Re: Different marine growth rates on hulls, Sydney areas !

PostPosted: Sat Jan 18, 2014 5:42 pm
by DESIREMK1
Hi Guys / Gals ,

Next weekend im taking our Mk1 up to our new Private Mooring at Mooney Mooney Creek , surrounded by Oyster Farms . Before gaining a spot at Parsley Bay , So it will be interesting to find out how much related growth its stay in Mooney Mooney Creek will produce , when she gets taken out for Anti Fouling in August .

Brad
DESIREMK1

Re: Different marine growth rates on hulls, Sydney areas !

PostPosted: Sat Jan 18, 2014 6:18 pm
by SeaLady
Mooney Mooney Creek will give you lots and lots of slime.
Very, very quickly.
There is a reason most up river boats use River Scum Black colour antifoul.

The mooring line grows interesting marine life.


AND!!!! according to a book about the Hawkesbury....

Thar be Sea Horses in Mooney Mooney Creek!!!!!

I have never spotted one but apparently they are there.

Re: Different marine growth rates on hulls, Sydney areas !

PostPosted: Sat Jan 18, 2014 6:19 pm
by SeaLady
Oh...

Be careful of the 'speed hump' in the western channel between Spectacle Island and the road.

I ran aground on it with the dinghy.
And yes... I was in the channel.

Re: Different marine growth rates on hulls, Sydney areas !

PostPosted: Sat Jan 18, 2014 9:06 pm
by Phillip
Up here in the Camden Haven River we have bursts of marine growth!!

This last week or so its been cunjevoi, so much had grown on my anchor rope that I had to take a spade to it to get it off!

During the large tides last week the yacht downstream of SEAKA was moving all over the place due to the very large build up of cunjevoi.
Seaka was doing much the same!

We also find that propellers attract barnacles unless you attend to them on a regular timetable.

Re: Different marine growth rates on hulls, Sydney areas !

PostPosted: Sat Jan 18, 2014 9:58 pm
by DESIREMK1
Hi Guys / Gals ,

It would be interesting to hear from a Parsley Bay Top Hat Owner , In regard to their experience with Marine Growth on the bottom of their hull , and what Anti Foul they have found , to be most effective ?

Brad
DESIREMK1

Re: Different marine growth rates on hulls, Sydney areas !

PostPosted: Sun Jan 19, 2014 5:19 am
by Topi
If you leave the boat unattended for a time at Mooney Mooney you might be harvesting oysters when you return :)



A trick we use for the prop - Whenever we plan to leave the boat for a period of time we put a strong garbage bag on the prop & tie it on very tight to restrict water flow in and out of the bag. If it is for a very long time we first put an old Tshirt over the prop so the blades do not wear through the plastic bag too easily from water movement.

When I last removed a bag off our bigger boat it has been on there for 5 months. The bag had just worn through on the tip of one prop blade and the only growth was a single hairy weed like thing. No barnacles & the prop is uncoated, just raw bronze.

The next time I have to do it, I will use some old thick socks, one on each blade and then the bag over the top.

The Top Hat we now have is powered by an outboard, so I may not be using the trick for a while.