Edit June 18, 2020: Having tested this boat, it works fine and looks great especially if you want to have a two colour design with regular shaft drive. I have gone back to the single colour version and designed an RNLI version of this boat with all the kit to make a great looking rescue boat. It's coming soon!

This is a very customised version of the RC boat from Sergey2484 prinicpally to make it possible to be more like a real boat.

It's all done on Tinkercad by me as a hobbyist. It works, looks very tidy and you will have lots of fun :-). LOA (Overall length) is 916mm.

I also wanted to make some commonality with Barspin (Daniel Noree) engineering work on the OpenRC F1 car I also made. To do that I modified the servo holder and motor mounts and pinion so you can fit the same electrical "hardware" from the OpenRC F1 car right into the boat. Motor RPM and prop size is related - high RPM is not always great in water. I used a lower rpm 55T rather than the higher rpm 35T in the car. It's great fun and plenty quick enough in either application. You could of course go brushless, but too much RPM will turn the prop in air and I didn't want to redesign it for any water speed records.

I wanted to enable this to be two-colour printed to give a finish more like a real speedboat. This meant splitting each section into a hull and top section. From the front to back, they're labelled 1 to 5 as you'll see from the STLs

You need to assemble the hull sections first using silicone sealant and M5 bolts (see below) using the propshaft (fits between hull 4 and 5) as a guide to make sure it all aligns well. When dry, remove any excess silicone, sand the hull lightly and spray lots of car laquer spray from DIY stores or car accessory dealers to seal the hull and make it slippery.

Then print the top sections, add a small bead of silicone sealant and bolt these together. Using a shower seal held into place by sealant along the top edge of the hull section, place the adapter blocks in hull 2 and 3 and then bring the top section down onto the hull and tighten up. It's just like how you build a real boat to marry these two sections. If you have any polystyrene, fill voids in case you smash into something and want to save your boat from the depths.

Enjoy!