Marine keel cooler

Claim 1

For use with a vessel having a hull and equipped internally with an engine or similar accessory having a water circulating pump; a keel cooler comprising a header unit attached to the underside of the hull and communicated through the bottom of the hull with the pump, said header unit being vertically divided by a partition into two chambers providing outflow and inflow of water relative to the pump, a return fitting attached to the underside of the hull and spaced longitudinally from the header unit and at least one cooling tube connected between the header unit and the return fitting, said tube having a longitudinal flat divider plate extending centrally thereof for the entire length of the tube and dividing it into two equal and separate flow compartments for the flow of water of the same volume from the header unit to the return fitting and then back from the return fitting to the header, said tube being longitudinally fluted and being provided with a series of diametrically opposing internal grooves extending the full length thereof and separated and defined by internal radial projections extending the full length of the tube and said longitudinal divider plate having opposing side edges sealingly fitted in a pair of diametrically opposing grooves.