Porpoising — bow bouncing

The bow bounces up and down instead of running flat on top of the water.

Try these in order

Make one change at a time and re-test — that's how you learn what your car likes.

1. 1
   Lower both trim tabs

   Forces the bow down so it stops riding on the keel tip.

2. 2
   Check/raise motor or strut height if the cavitation plate is buried

   Wrong drive height is a root cause, not just a symptom.

3. 3
   Add a ride plate if running an oversized motor

   Prevents porpoising at full throttle on an over-powered setup.

General RC tuning guidance — your chassis manual's own tuning chart is the final word for your specific car.