How to Modify your RC boat propeller. Instruction plus test run

Modification of RC boat propeller: de-tongue the prop, by cutting it, sharpen it and check the balance. Followed by a test run with my DIY Cozy F1 Tunnel. Motor: https://s.click.aliexpress.com/e/_EHB... For a 18-22" or 45-60cm rc boat, this is a perfect upgrade motor. 3S = great speed 4S = crazy speed