Is it really worth Antifouling?
Should I antifoul my boat?
It's not the most interesting topic, so to put it simply this is what we would recommend.
Are you leaving the boat in water for more than 3 weeks?
If it's a YES then I would recommend antifouling your hull. If it's a no then it might not be worth the effort and cost.
Why 3 weeks?
Salcombe is rich in biodiversity and high current moorings. This provides us with an abundance of crabs and vast sea grass meadows, however it also provides the right habitat for life to grow on your hull.
The Science
Your hull might seem nice and smooth but it's actually full of tiny microscopic holes that plants and crustaceans can latch onto and start their growth.
If your boat is taken out of the water and given a good pressure wash before the growth can get a good hold, then it should come off easily with little to no hull damage. Another less effective but more fun method is to give your boat a good high speed blast which hopefully dislodges some of the growth.
After a few more weeks however the growth starts to really cling onto your hull and barnacles will start to form. If given enough time barnacles will form thick calcium deposits on your hull which are extremely hard to remove, even with chemicals or pressure washing. If there are enough calcium rings then this will start to cause drag and decrease speed and fuel efficiency.
There are lots of different types of Anti-Fouling products available and below are some of the more popular options.
This photo is from a new customer's boat. My recommendation to him was to increase the height of the black antifoul. You can see here that It has done a very good job at stopping any fouling. However, it was not high enough and therefore barnacles started to grow below the water line. This was after a full season on a mooring at Kingsbridge.
Hard Antifoul vs Self Polishing
A hard antifoul clings to the hull for the year, a self polishing antifoul starts to fall off after a period of time.
When it comes to a paint on antifoul, I always recommend a hard antifoul over a self polishing antifoul. This means that the paint clings on to your hull for longer and therefore protects the hull for longer. It also has less biological damage as the antifoul doesn't flake off into the sea and instead clings to the hull.
Both antifouls work in the same way, they are full of copper and zinc which prevents the growth of sea life.
Copper coat
Copper coat works in the same way as a hard antifoul, however they don't need to be re applied annually and therefore won't build up on your hull. There is however a much high cost to this type of coating, but with a rough life time of 10 years. It is recommended to lightly sand the coating every year to reveal a clean layer.
Again the biological damage is less than the hard antifoul as less pollutants are released into the sea.
Other options
Silicone can be used to form a "slippery" surface on your boats hull. However the silicone is very fragile, this can't be used on a roller trailer or dried up on a beach.
Larger ships use ultrasound which deter organisms from sticking to a hull. However the wider understanding of biological damage is currently unknown.
A new ceramic product is currently being tested and could be a revolutionary leap forward. It will be a super smooth finish that's hard wearing and completely non toxic. This would no doubt increase fuel efficiency and top speeds as well.