Switeh the frogs.

To solve the puzzle, select the following frogs: B, D, E, C, A, D, and C (P).

Take the wave piece (Q).

examine the gate.

Zoom into the lock and place the SHIP and WAVE PIECE on to trigger a puzzle (R).

Raise and lower the waves to get the boat across.

To solve the puzzle, select the following waves: A x2, B x2, C x2, and D x2 (S).

Go forward through the newly-opened gate.