Coleman Marine Diesel, Inc. has been firmly committed to providing quality products and excellent customer service in Shelter Island, San Diego since 1983.

We are factory authorized warranty dealers for Cummins, Onan, MAN, Twin Disc, ZF Marine Gears and Lifeline Batteries.

Experienced and skilled staff are available to assist with your purchase of engines and generators as well as complete servicing of your vessel.

We offer a complete spare parts inventory including Fleetguard Filters and Lifeline Batteries.


Comprehensive inspections for pre-purchase used boat engines, transmissions & generators provide you with peace of mind prior to sale.