If it's just a bad receiver, it shouldn't be too hard to replace the electronics. The bigger question is did the manufacturer use standard parts or an integrated receiver and speed controller?
I was just doing a bit of research online and found your boat is made by Pro Boat, a subsidiary of Horizon Hobby. This makes things easy. Since they have a customer service department, give them a call and see what they can do to help you out. Their number is 1-800-338-4639