I recommend the Micron series, if available. 

GelSeal is not required on an Amel made after about 1985. In the mid 80s Amel began using a proprietary anti-osmosis layer between the gelcoat and the fiberglass. 

A high quality antifouling paint, proper preparation and application of at least 2 coats with a 3rd at the waterline, leading edges, and rudder will consume most of 20 liters. 

International makes antifouling in 20 liter pales, and 20 liters will allow the above number of unthinned coats for a SM, 54, or 55. This method should give you a very high chance of renewing the antifouling every 2 years. Of course, antifouling life depends on quality of product, preparation, application, number of miles and location. 

Best,

CW Bill Rouse
Amel Yacht Owners School - www.AmelYachtOwnersSchool.com
720 Winnie St
Galveston Island, TX 77550
+1(832) 380-4970

On Mon, Sep 30, 2019, 9:13 AM Paul Brown <feeder.brown@...> wrote:

How many litres per coat is required for a 54? I expect a 55 is not much or if any a larger surface area and I generally use 12 litres for 2 coats but maybe this is not correct?

Regards Paul Fortuna II 55/17

On 30 Sep 2019, at 1:14 pm, David Crisp <david@...> wrote:

Many thanks to you all for the rapid response, advice and a clear consensus.   I'll go with 2 coats of the 350.

Great to back aboard an Amel again.  About 15 years ago I bought a SM near Nice and took her to Caribbean and back to the UK during a 3 year sabbatical.  This time I've just retired....  So far, after a month, very pleased with the 54, she has many of the improvements I imagined in my mind whilst living aboard the SM.  

Fair winds and following seas to all.
David
SY Wilna Grace