Back in the days of the Sailing Ships, the Navy (and all vessels) placed their bathrooms at the front (the bow, or Head) of the ship. (The "Head" also is a reference to the ornate decorations of Mermaids found on the bow of many vessels). Anyway, you might think it funny to place a bathroom at the front of the ship. Each time the ship moves, the smell should flow back over the rest of the ship, right? No, because this was in the days of sail. In order for a ship to move, the wind had to come from behind, catch the sails and move the ship. The wind would always move faster than the ship, thus carrying the smell away from the vessel.