Trouble is, how far is home? I can manoeuvre my 4 ton sloop with a 2 hp outboard, then sail it a hundred miles. Upwind, downwind. I don't care. How far are you going to limp the motorsailor upwind? I don't see any way of avoiding the 9.9 long shaft solution if it's any distance.
Yeah, same motorsailer but just got a 4hp engine and an outbd bracket at the jumble so not sure weather to put them on the speedboat or the main boat as a backup.
Home is any port if the main did break, this shouldn't happen being new, but after the problems with the old BMC engine i thought a bracket on the back may be a good idea and the outbd. is always onboard anyway so.....?
Also will make a good foothold if someone fell in.
I reckon i might try it, atleast 4hp would get into a marina.(if the sea was calm) Even 8 or 10 wouldn't work against the tide in the Bristol channel. We hit over 10knts with current and punching it drop to sometimes 2kts with 39hp inbd.
Now little lad is nearly 3 we will resume or old tactics which is lots of night sailing and my biggest worry is pot lines around the prop so atleast it is one less worry knowing we can motor the last bit through a lock. (i'm never diving under again with a drysuit in a big sea!)
Depends where you are & what you are trying to do. Square riggers have been towed by a five oared whaler in the past. I manouvered my 31' Ketch in dock using a 2hp o/b on a rubber duck tied to its side. Given a headwind and/or strong tide a 10hp might struggle. Short steep seas can also cause stern mounted o/bs to come out of the water - even if a long shaft.
I expect your 4 HP would move your 6 Ton boat if the wind or tide was not strong. I was able to get my Macwester 26 approx 3 tons back into Chichester harbour when Petter mini twin let me down when there was no wind. We used our Seagull 2 HP. The only problem we had was not much petrol on board, so we had to scrounge off the harbour master and pay back later. So if you are going to rely on this OB make sure you carry plenty of petrol.