Should you go underwater in a tsunami?
No. Because of their long wavelength, tsunamis act as shallow water waves. One property of shallow water waves is that the horizontal fluid velocities under the wave are independent of depth.
Can you feel a tsunami underwater?
The crests of tsunami waves may be more than a hundred kilometers or more away from each other. Therefore, passengers on boats at sea, far away from shore where the water is deep, will not feel nor see the tsunami waves as they pass by underneath at high speeds.
Can you survive a tsunami while in the water?
If you are in the water, then grab onto something that floats, such as a raft or tree trunk. If you are in a boat, face the direction of the waves and head out to sea. If you are in a harbor, go inland.