It sounds like you have an RTS boat.
It is usual for them to be nominally tuned to the middle of the 27Meg band, but they often don't use crystals for tuning, relying on the use of inductor,capacitor and resistance.
It is usually cheaper in the long run (because it works) to buy a complete replacement radio set with all the appropriate bits included, and go that way. These normally have a transmitter, receiver, a pair of servos, crystals and a battery box. You have to find the batteries and usually a speed control - sometimes you can get a deal where you get one servo but have an ESC included.