On owning a sail drive

And another...HAUL OUT MONDAY!

Most Pretorien's came with sail drives. Sail drives are relatively common in European boats.

For the non-boaters, most boats have a stick coming out of the hull (prop shaft) that points backwards and has a propeller at the end of it. Inside the boat the engine (or really the transmission) is connected to the shaft. The shaft spins, the prop spins, and off you go.

In a sail drive, half of the transmission pokes out of the water. Ours looks like this:



Why a sail drive? I don't really know because I've never owned a prop shaft to compare it to. People say sail drives are better, but probably only those who own them and are rationalizing. I know that we don't have the same amount of prop walk -- prop walk is when you switch to reverse and the water coming off the prop causes the boat to move sideways in the water for a moment. This can really suck in tight places. I think this is partially because the prop is relatively close to a hull on a prop shaft and not as close on a sail drive. Because we are deeper we are also supposedly less likely to foul our prop on anything close to the surface.

Sail drives scare people because they are big holes in a boat. However, the seals that keep the water out of the hull don't fail. Sail drive seals do fail - the ones that keep the water out of the transmission oil itself. This sucks but not in a I'm-going-to-die kind of way.

The most annoying thing about a sail drive is that changing the transmission oil is most easily done by removing what we have been calling "the jesus bolt" in the bottom of the sail drive which can only be done while out of the water.



Open this bolt, crack the fill cap and the oil gushes out. You can also pump the oil out of the top of the transmission.

For us, the other annoying thing is that our sail drive requires removing the prop to change the zinc anode and we have a complicated (but fantastic, expensive and bought by the PO) prop to remove and this also needs to be done out of the water.

Imagine our delight when we found an adapter which will allow us to convert our zinc to a split (cuff) zinc and thus be more easily changed by diving on the boat! Unfortunately we found it too late for this haul out but I will be buying it and we will install it next year.

Finally, there is this rubber gasket at the hull which prevent growth up inside the cavity where the sail drive's hull seals are. Ours had not been painted and so we were afraid to paint it last year without finding out why. Turns out, as far as I can tell, there is no reason so we painted it with the same aluminum safe paint that we use on the sail drive.



Here you have the gasket pre-painting but post-powerwash and scraping. As you can tell, we had a beard of mussels and barnacles when we came out of the water.