That is a totally inappropriate motor for 2S, you will burn up your ESC and motor. You want a motor Kv between 3000 and 3500 rpm, the motor size you have is okay. Do you have water cooling? Try an Octura x427 prop.
As above, the rudder is needlessly long, you only need 1.5” in the water. No need for a standard size servo either, a decent mini or micro servo will work fine in that tiny boat.
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