Art; I suspect a drivesaver would only be a Band-Aid for the shaft, while ignoring a possibly bigger problem working on the rest of the system. As such, I would not suggest it as a first step. The fact that the engine zinc is being eaten at a greater rate then the other zincs raises the question of why??? The whole subject of galvanic and electrolytic corrosion is a complex and difficult subject with no easy answers. The two main questions that have to be answered first are: 1. is this stray current corrosion coming from leakage off the boat's (or another boat's) electrical system, or 2. is this galvanic corrosion coming from mixing dissimilar metals (this is what zincs are intended to protect against)? If you do not have a good understanding of electricity, it's time to call in a specialist. If you are comfortable with electrical systems and the why and how of their workings (since you've already been in the bilge with a meter, I suspect this may be the case), you might want to take a look at two books: * - Boatowner's Illustrated Handbook of Wiring, Charlie Wing, McGraw Hill (ISBN 0-87742-383-0). This is a great all-around standard on electrical systems on small boats (<65'), that also contains a good chapter on corrosion. This is a must-have book for anyone doing their own wiring. * - Boat & Yacht Corrosion Control by Yacht Corrosion Consultants, Inc (available from West Marine) Good luck with the hunt, Kevin -----Original Message----- From: AFNMD@aol.com [mailto:AFNMD@aol.com] Sent: Sunday, September 26, 1999 7:01 PM To: kredden@injersey.com Subject: Voltage in bilge Keven, Sorry to impose on your expertise again but in rereading your reply I got an idea. Would a drivesaver help. It would put a non conductive "donut" in the driveshaft isolating it from the engine. If it would not help my shaft or rudder zincs would it help the pencil zinc in the engine cooling system? Thanks, Art Lady Jane