Shamrock was scratch built from after reading an article in the April and May 2010 editions of Model Boats from plans (ref. MM1472). This article concluded with the words "there is nothing difficult about scratch building, so give it a go". The model has a 540 motor and 7.2V power supply, with a separate 6V battery for the working navigation and search lights. The plan is excellent in setting out the build sequence. The various profiles are accurate in dimensions giving a trouble free build. Made from light ply and 1/32 plywood it was a pleasure to build.
On the water the model planes quite well, but I am considering whether to increase the power to 9.6V. The canopy was constructed from brass tubing resulting in a slightly "top heavy" tilt when turning. Scratch building Shamrock gave me a lot of pleasure both in building and sailing.