planche à voile
wind surfing
planche a voile! (in French)
the sailboard (surf)
"Une planche à voile sur la mer" (on/above the sea) is better. You could hear "dans la mer" (in/into the sea) in conversations, but the correct usage would be for things under the waves.
a surfboard is called 'une planche de surf" or 'un surf' in French.
Either would be okay - but the second phrase is more accurate. Windsurfing on the sea as opposed to Windsurfing in the sea.
la planche means the plank, the wooden board in French.
un voile de soie is a silk veil in English.
It means he nearly drowned while doing some surfing
"Sail" as a feminine noun and "cloak, curtain, mist, veil" as a masculine noun are English equivalents of the French word voile. Context and other hints to the noun's gender -- such as adjectives, definite articles, indefinite articles -- make clear which form suits. The pronunciation will be "vwal" in French.
Voile = Presto!