An amusing video has emerged of a windsurfer crashing into a lake near Hanover, Germany.

In the footage, captured using a GoPro camera mounted on a board, windsurfer Marcin Grześkowiak can be seen speeding along a calm lake at 50km/h until he passes a flag and suddenly smashes into the water.

According to Marcin, the flags normally warn surfers about fishing nets placed deep beneath the water, but this one was a little closer to the surface than he realised.

Fortunately, Marcin was not seriously injured in the fall.

An amusing video has emerged of a windsurfer crashing into the sea off Puck Bay in Poland (Hel Peninsula).

In the footage, captured using a GoPro camera mounted on a board, windsurfer Marcin Grześkowiak can be seen speeding along a calm lake at 50km/h until he passes a flag and suddenly smashes into the water.

According to Marcin, the flags normally warn surfers about fishing nets placed deep beneath the water, but this one was a little closer to the surface than he realised.

Fortunately, Marcin was not seriously injured in the fall.