Rotating the propeller fixed for sailing

These days I happened to read the owner’s manual of the boat and called my attention to recommend not engage the reverse gear while sailing. I do not understand what the point is this, because it seems that the propeller must rotate freely offer less resistance to being blocked.

Fortunately, my engine (volvo penta 2030 saildrive propeller 2 blade fixed) seems that it is recommended that the propeller turning, but the caveat that we must start the engine every ten hours 5 minutes to cool and lubricate the investor and tail (which leads).
What do you think? A greeting. Am?ndio

Hoi Am?ndio,
If the propellor rotates, it is indeed possible that the oil get to hot en need to be cooled by starting the engine and circulate the water through the tale over the saildrive. If you put the gear in the reverse position, you will fix the propeller. This means that you have more resistants if you are sailing, it will cost you about 0,7 - 1 knot speed. Maybe, what they mean in the book, is that the resistance, if you put the engine in the reverse gear, to big for the teeth-wheels (good translation?) of the gearbox, that the will damage by doing so.
If you buy a folding 2 or 3 blade propellor, you will be lost from this problem. I have a 2 blade folding propellor and when I stop the engine to go sailing, I put the handle in the reverse gear for a moment, to close the folding propellor. After that in neutral and we have no resistance during the sailing and no problem with heating up the oil.
Ciao,
 

Hallo Amandio, its no problem to fix your prop, there s not any chance to damaged the tail or the gearcase , i did it for years, also when you put your gear in neutral so that the prop rotates there s no chance to damaged or overheating, because your tale has no engine cooling, the  cooling is only to cool your engine block and cilinderhead, and the tale is under water you cand emagine a better cooling. Sorry Hans but the things you write are wrong exept the speed thing, i am an engineer and now a lot of these things.
 
Regards Willy.