DandV

An interesting read on experiences running V8 tourist jet boats on LPG in NZ. Shotover Jet ran a number on LPG for some years, but now use two standard petrol Mercruiser 350hp V8 motors in each boat, but have converted one to electric as an ongoing trial. Perhaps over powered for a narrow boat? https://www.jbnz.co.nz/yabbse/index.php?topic=7624.0

Is it necessary? Depends what you want. Is it a good idea?. Well if you want your coating system to better protect your hull, yes. Basically, if you use good quality materials, and a competent applicator, you will get what you pay for. You will be paying all the fixed costs for dry docking, and the set up, and clean up costs, of blasting, and painting. The incremental additional costs of adding the base plate area to the submerged hull sides for coating is modest in comparison and very definitely should be considered. Hot sprayed zinc is best, but high quality inorganic zinc paint is still very good. Both effectively act as an overall anode, protecting any areas of immediatly adjacent steel after being exposed to any coating damage or application defects. Then overcoating the zinc coating with a compatible coating then reduces the exposed area of zinc, thus it's attrition when exposed. This preserves its availability when scrapes and dings exposes the adjacent steel to corrosion. As people have said, coating manufacturers who supply specialist protective coatings, publish specifications for the correct preparation and application of a system of their compatible products. And some even have recommendations and procedures for maintenance, and damage touch ups. For instance International Paints used to have a nice handbook on narrowboat painting with advice on their paint systems. Firms specialising in this work also are generally knowledgeable on what works best for particular applications.