Saltwater options

[jhnmdahl]

Many of the Volvo and Mercury engines available in Cobalt boats have saltwater-specific drive units for saltwater. Add that to a freshwater cooling system (as opposed to using seawater), and the drive system will last much longer, especially if left docked in saltwater or brackish water.

Volvo's OceanX includes a titanium-ceramic coating, and sensors that monitor the condition of gear lubricant and bellows integrity:

http://www.volvopenta.com/VOLVOPENTA/NA ... ceanx.aspx
http://www.boattest.com/engine-review/V ... 016_OceanX

Mercruiser's Seacore drive unit includes hard anodized aluminum parts, plus battery-powered biasing the drive unit to prevent galvanic corrosion. Stainless steel and freswhater cooling are also employed to reduce the effects of saltwater:

http://www.mercurymercruiser.com/mercur ... ystem.aspx
http://www.boattest.com/Resources/view_ ... NewsID=301