Originally Posted by jgrace
OTOH my Yamaha dealer tells me an auxiliary should have the same shaft length as the main engine.
I have option A, for the simple reason that my main engine has an XL shaft and is mounted in a cut-out section of the transom, and there was no auxillary with a shaft long enough to be the same length as my main engine.
At displacement speeds I really can't see this making any difference TBH!! Ours pushes us along nicely at around 6-7kts. One advantage of having engine mounted as in option A is that it reduces your draft so you can use your aux to get you into shallow places your main engine can't.
Also you probably won't be able to use a long shaft on a tender, which can be quite handy if there's a gale blowing!!