Brief observations on anti-fouling
The upper reaches of Portsmouth harbour are particularly bad for fouling, with weed, slime and barnacles. For a number of years I had used Awlgrip, expensive but effective, with no time limit between coating and immersion so antifouling could be applied at any convenient time over the winter.
For 2001 I experimented with SeaJet as a cheaper option and with reasonably good reviews in the press. The result was not too bad but with definitely a faster and thicker growth of slime and weed than with Awlgrip, to which I returned for the following season.
When the boat was due to be launched in 2003, in an unexpected hurry, I found I had three-quarters of a tin of Awlgrip and a similar amount of Seajet, left from previous years. So why not experiment - Awlgrip to port and Seajet to starboard. Once launched, the boat was sailed to Milford Haven where it remained in the water for that season and the next. The summers were spent on a swinging mooring and the intervening winter in Milford Marina.
Observation from the surface indicated a much lower level of fouling generally in Milford Haven than in Portsmouth Harbour. In particular the weed growth on the waterline, which in the past could reach several inches over a month, was very light in Milford. The slime was also less persistent, clearly diminishing in the winter months. However from the surface no real comparisons between the sides was possible.
The Brigand was lifted out in October after 18 months in the water. There was light to moderate slime growth and light weed growth along the waterline on both sides but noticeably less on the Awlgrip side. Nevertheless the Seajet side was still cleaner than an Awlgrip treated hull had been in Portsmouth. Unfortunately I had forgotten to take my camera down so visual evidence is lacking. By the time I next went down the yard had pressure washed the hulls. I was pleased to note that the hull on both sides was exceptionally clean, with little elbow grease needed before applying next year's anti-fouling.
So what have I concluded and what to use next year!
Firstly this confirms "horses for courses". When I sold antifouling as a chandler, and gave talks on it, I always said that the local conditions should determine how much to spend on Antifouling, and this little experiment has supported this. Now that I am in a low fouling area with little weed I believe that the average boat owner here can spend considerably less on antifouling than his Solent counterparts (not to mention the savings on Marina Fees etc.). Even with Awlgrip we had to scrub the bottom at least twice a year if racing in the Solent.
However I am tempted to stick with Awlgrip if I decide to only come out of the water every other year and if I am likely to cruise to areas of higher fouling.
Peter Royle
Brigand Chief