I have a Brushless thumper on 18 cell ni-mh, 55mm prop. in my MFA Avenger. Makes a wonderful engine sound. And with the heavy batteries ploughs through the roughest waters. They did use gell cells, and they are heavy.

What a great bit of luck ! . I have an Overlander Thumper brushless running on a 4 cell lipo in my Spearfish, give's me an hour of skipping round the pond . if you want it to be a missile though I have seen Leopards motors fitted in them . Have a look at my Harbour pics . Also check out Youtube for inspiration . Happy Boating 👍