Fouled sterngear - a scientific test (sort of)

[MapisM]

Ok, actually not scientific at all if I'm honest, but I'd be interested in your views anyway.

The background is that I have the habit of brushing the barnacles from sterngear while having a swim.
In my experience, it's worth doing that regularly (say every couple of weeks), because the nasty creatures are easier to remove when they are little, and it rarely takes me more than 15 mins or so for a decent cleaning.

This year, I left the boat unattended for exactly one month, from beginning of Aug to a few days ago, and I found some unusual growth, but just on the fixed flaps which are attached to the transom.
I was already half done with cleaning when I thought to grab the GoPro, so the port side flap is already cleaned (and that is just about the situation in which I left them one month ago), while I had only began to brush the border of stbd flap. Therefore, it's easy to compare and see the one month growth I was talking about.
You can also see the props and rudders, which were actually pretty clean and didn't require any brushing.
For the records, the a/f used was the same for all the sterngear metallic components.

Now, I can't recall to have ever experienced in the past neither such fast growth on the flaps in just one month, nor such difference between them and the lower/deeper metal parts.
Wadduthink, are the critters evolving, and beginning to appreciate sunlight better than sea water...? :ambivalence:
That's the only difference between flaps and props/rudders, in fact: the first are just 5" or so below the w/l, and well exposed to sunlight, while the latter sit a couple of feet deep in the water, and are never under direct sunlight.

 

[BartW]

MapisM I don't think these are barnacles, but algea or sort of weed that only grows in light,
and perhaps because the boat was not moving, the seeds could better attach and better grow

sometimes I see similar growth on the sides or stern of BA, but only where light comes.

early this summer I had to leave my Karnic for 5 weeks in the water, without antifouling,
the boat didn't move in that period, and when we came back, she had 10cm growth on her sides, green weed or plants (?)
especially on the side exposed to sunlight, (she was moored on the side)

on the bottom was much less growth and that was brown.

loaded with divers she could hardly get on the plane, but after a few miles, she became gradually cleaner and speed increased

 

[MapisM]

Yep, the larger dark red spots are indeed different things, but those are relatively easy to remove, and I understand (sort of) that they can grow fast.
Otoh, there were indeed several biggish barnacles, up to 1cm or so in diameter.
They are visible in the clip, though I understand that it's not easy to distinguish them.
But you can see for instance a couple of them also in the still pic of the youtube video, right at the bottom left.
And several others are also on the vertical part of the flap, the one attached to the transom.
Those are the critters which drive me nuts.....

 

[Nick_H]

I know this thread wasn't strictly about sterngear antifouling, but i've had great results with Velox Plus.

It was put on the props and rudders in June 2013, I had no fouling at all for the rest of last year, and just a few small barnacles starting to grow by end of July this year, removed in a few mins with a scraper.

 

[MapisM]

Funny you should mention Velox Plus, it's the same stuff that also my yard uses for sterngear.
When you say Jun '13 - Jul '14, you mean with the boat always in the water, I suppose? A whole year with no fouling is indeed an impressive result...!
Did you also experience a somewhat higher growth on trim tabs, compared to props/rudders?

 

[Nick_H]

Yes, a year in the water, though to be clear it was no fouling for the remainder of 2013, then slight fouling in 2014. Far better than anything else i've tried though.

There was certainly more fouling on the trim tabs, but they weren't treated with Velox, so not a suitable comparison.