Keel cooling
R.W. Fernstrum & Company
Menominee, Michigan maker of GRIDCOOLER keel coolers since 1945; also builds WEKA Boxcoolers in the US and supplies OMEGA Laser Plates.
Keel cooling
3 companies
Hull-mounted external heat exchangers: engine coolant flows through tubes outside the hull and is cooled by the surrounding sea water, eliminating raw-water pumps and strainers.
Filter companies: Keel cooling
Shaft bearings
Duramax Marine
US maker of Johnson Cutless water-lubricated shaft bearings and DuraBlue composite stern tube bearings and rudder bushings.
Box coolers
WEKA Marine
Dutch box cooler specialist (since 1957) making CuNi, aluminium-brass and steel coolers; sister company of Fernstrum, whose keel coolers it sells.