kts. Guidance system Fibre optic cable, dual mode sonar, inertial Launch platform Surface ship, submarine The GWS.64 Mako is the current anti-submarine and anti-ship heavyweight torpedo (HWT) in service with the Royal Isselmere-Nielandic Navy . The torpedo has a body diameter of 533 mm (21 in). GWS.64-1 Type: Heavyweight general-purpose torpedo