The Mark 18 did not produce a wake of bubbles or turbine exhaust pointing back to the submarine firing it - a major advantage in daytime engagements. The torpedo also lacked the depth-keeping and exploder problems that had plagued the Mark 14. The disadvantages were the low speed compared to the Mark 14's , the need to regularly withdraw the torpedoes from their tubes for recharging, sensitivity of the batteries to water temperature, and onerous maintenance procedures. The Mark 18 shared one major flaw with the Mark 14: it had no protection against circular runs, a defect which claimed "Tang" for certain, and possibly other U.S. submarines, as well; "Donc" Donaho's "Flying Fish" was nearly sunk by a trial model in October 1943.