What Gear Should You Be In While Sailing?

There is a common discussion among sailors on what gear you should be in while sailing. You have turned the engine off, raised the sails and are crusing along. Should you be in forward, neutral, or reverse? The issue is that water is flowing across the propellor, which then can potentially turn the shaft, which then turns gears in the transmission. Almost everyone agrees that being in forward gear is a bad idea. This just wrecks the transmission. So that leaves neutral or reverse. In neutral, the prop freely turns as the boat moves, but the transmission is disengaged. If it is in reverse, then the prop is held in place by the transmission. Some people don't like the sound of the prop and shaft turning. The problem is that if it is reverse there is pressure being applied the the transmission, which causes wear and tear. This is what Yanmar says:

Advisory Number: MSA08-003
DATE: February 8, 2008
TO: All Marine Distributors, Dealers and OEMs
SUBJECT: Gear in Neutral While Sailing
MODELS: All Sailboat Engines

We continue to get questions regarding the
correct gear position while sailing with
the engine OFF. This advisory is issued as
a reminder; Yanmar requires that if
sailing with the engine OFF (not running)
the transmission shifter must be in the
neutral position or internal damage to
the gear or sail-drive will result. This
damage will not be covered by Yanmar’s
Limited Warranty. Please instruct
customers and dealers who deliver the
sailboat to the customer, of the correct
(Neutral) position for the marine gear
while sailing.

If the customer desires that the
propeller shaft not spin while sailing,
either a folding propeller, shaft break,
or other suitable device may be used.
However, Yanmar accepts no responsibility
for the selection, installation, or
operation of such devices. Please also
refer to Marine service advisory
“MSA07-001 Yanmar Sail Drive Propeller
Selection” for additional information.

So they give the alternatives. You can have a folding prop, shaft break, or other suitable device. If you have a folding prop, the gear still must be in neutral. The prop being folded will cause the shaft to spin minimally. If you have some kind of shaft break, then potentially the prop can be locked, because the shaft can be disconnected from the transmission.

While the advisory above is for Yanmar engines, I don't see how it doesn't apply to all makes of engines. Having just spent thousands of dollars to get the transmission on Achernar rebuilt, we are going to do everything we can to protect our investment.