The Omer 4 submarine was designed and built during the 2000-2001 period and was used during the competition of 2002. Omer 4 is a one-person submarine with a propeller.

Omer 4 was the first submarine equipped with an electric direction system. The command made by the pilot were transferred to an inboard computer. The computer was controlling 4 electrics motors linked to the fins at the end of the submarine. Furthermore, the variable pitch is now electronically controlled as well. The hull of the submarine was also improved, it is made of carbon fiber with a core of high density foam.

The fastest speed reached by Omer 4 was 7.192 knots. This speed was recorded at Bethesda, in the Maryland in the United states during the 6th international submarine race in 2001. This speed was the world record for a one-person submarine with propeller, until its successor Omer 8 beat it.

The submarine is currently exposed with respect and honor at the École nationale d’aerotechnique at Saint-Hubert In Quebec.