The Royal Australian Navy, however, continued to use it alongside its successor for a number of years, because the Mark 44 was thought to have superior performance in certain shallow-water conditions.

After some fine tuning of the design, an enhanced version the Mark 44 Mod 1 entered United States service in 1956.

However shortly after the torpedo entered service it became apparent that newer Soviet submarines were both faster and deeper diving, and could potentially both outrun and out-dive the Mk.44 which was designed to attack targets with a maximum speed of only 17 knots.

A South African package offered an extensive upgrade, replacing the warhead with a 45 kilogram shaped charge device capable of penetrating 40 millimeters of steel behind a 1.5 meter water filled double hull.

The package also included a comprehensive digital electronics upgrade tripling the target acquisition range to 1,000 meters in ideal conditions, and containing a number of counter-counter measures along with a variety of attack modes.

Finally is the propulsion section which houses the electric motor, four rectangular control fins and two contra-rotating propellers.

On impacting the water the torpedo either runs out for 1,000 yards (910 m) or performs a dive at a 30-degree angle to the search depth.