mikesn9 is correct. Slow down and cruise at 10 knots. Historically speaking most boats when leaving Pearl Harbor on patrol would stop at Midway and top off their fuel tanks before departing on patrol for Empire waters or beyond. Once you leave Midway conserve fuel and cruise at 10 knots to your patrol area. Once you reach your patrol area use 10 knots to patrol your area and use higher speeds when chasing targets.
