Scale MERLIN V12 V-12 Engine Kits for Thunderboats and Unlimited Hydroplane Kits. Kits available in 1/10th, 1/8th and 1/6th scales. Here is what Bret said about the kit: "Thanks for making such a cool 1/6 scale kit for the thunderboats. I soon realized that your kit gave me the ability to change or modify the parts and pieces easily to be able to customize it to fit my needs. Once I was done with the basic construction and paint I just went to my junk hobby parts drawer and dressed it up. thanks again! - Bret