What you see here is the oars locked into the correct position so the blade of the oar skims along the surface of the water giving lift. You see that the oars also make great rooster tails. Just like a water skier.
that the ship lifts out of the water. Modern ships heel under the force of the wind, but with the oars resisting the heeling action
the boat lifts instead. This lowers the drag on the boat as a whole.