First, the practice of towing the dink is just bad seamanship -- having said that, we've towed all of our dinghies at times, often in conditions where we shouldn't have. So far we've been lucky. But towing with a big motor
on increases the risk considerably, and the additional drag (at least on our boat) is very noticeable, so I for one would suggest that you develop a means of removing the motor
that doesn't strain back, mind or wallet.
We've dealt with a series of 15 hp 2-stroke o/b motors over the years, weights around 75 +/- lbs. Our method is to tie the dink alongside at the shrouds, attach the halyard
via a simple harness stitched up out of 1 inch webbing (that stays on the motor) and then lift
the motor off the transom. Once clear, I start walking aft, pushing the motor ahead of me until I reach the bracket which is on the outside of the stern rail. Meanwhile, Ann has wound the halyard
up a couple of feet, matching a mark on the line to one on the mast
. This brings the o/b's mount just above the bracket, I hold it in place and she eases it down in place.
The bracket is made up out of marine
ply and is held on to the rail with u-bolts.
Reversing this process gets it back on the dinghy
without strain. The only difficulty is if there is a big chop running and the dinghy
is bouncing... then some cooperation and timing is necessary! It's a good exercise in marital relationhips! I have done it solo, but it is much easier with two.
IMO, doing all this with the dink amidships where the boat motion is minimal is better than at the stern where motion from pitching is greatest. The dedicated hoist at the stern is not only expensive, but adds just that bit more weight in the far end of the boat and that much more stuff in the way of other activities.
Good luck with it all.
Jim and Ann s/v Insatiable II lying Church Point, NSW, Oz