The boat has a two year warranty , it sounds like the motor bushing or bearing is starting to wear or break up. Remove the motor yourself and send it back to the distributer with a covering letter . I am sure they will send you a replacement .
The boat is a very simple mechanical construction with no mastic seals or impellers . The boat really does lend itself to the home mechanic with a little mecanical sympathy.
Be careful when rebuilding not to overtighten the screws a light touch is the order of the day .