I don't think I can go through the hull because this would require a
different transducer I think. Don't want to spend more money that I
have to.

Yes, my initial reaction was that even with position A (closer to the
prop) it was probably far enough to (and in front of) the prop so that
disturbances may not play a big factor. But perhaps it is more
important than we think. Maybe I should play it safe and stick to B
location?

Note that I do not plan to use the FF much at high speed. What is
important to me is to get a decent reading at low speed (say while
trolling or trying to figure out depth to drop a crab trap). Cheers
and thanks for all the input so far! Andre