Hi Packy, first do you need a X2 Springer ? The standard size one could handle your 5ft model quite well, maybe up the power a tad. Your twice sized Springer will be bigger than you think and need a LOT of ballast and a big jump in power , brushless would be an option, it will be heavy to carry etc etc. Bang a standard sized one together on the cheap to see how it goes. If you do proceed with the bigger one 1/2" or thicker sides and bow/transom pieces. Dont know if doorskin would bend round the curves, if not cut it into 3/4" strips and plank it, sand smooth(ish). Coat whole hull inside and out with resin, quality epoxy and lighweight f/glass best or car repair polyester for cheaper smellier version. There are pics of a springer pushing a 1000lb pumkin in the water so your rescue boat doesnt have to be big. A kort nozzle and a 600 size motor will do it but just dont rush to the stranded boat or you will have a submarine on the way down ! You might want to consider a simple yoke on the front to make sure of a capture. Use plumber`s small bore plastic tube with foam insulation for floatation. The topsides can be simple and uncluttered so as to prevent snagging if you go into rushes or reeds to rescue something. Styrene sheet is OK for light work but I prefer 1/16th birch ply, well painted or resined. 1/8th" if you go with the big boat. Either way keep us informed with pictures. Attached is an idea for simple topside shape and another one to show that I`m not against enlarged Springers ! BTW that is X4.
