How long a shaft for trolling motor?

Short shaft, for sure - your motor on a dinghy is right on the water. . .

You are correct you need a short shaft motor. You do however need to be aware af the weight limit for the boat. The trolling motor is very light but the battery will weigh 60 to 90 pounds. So one person af 200 pounds is all you can carry. a second person to to much. weight..

confident,I even have had the comparable project as you. I had a 15" trandom on my catamaran an I actually have a 20'shaft on my evinride...I went an talked to the community boat shop. They reported if I fastened it an ran the engine i could kill the engine an my boat that way surely. SO he introduced me over to this wall with a number of those jack plates. i finished up getting a $2 hundred *handbook* jack plate. in case you get electric powered jackplates they weight alittle greater besides the indisputable fact that it extremely is as much as you. SO getting a jackplate is the answer. plus it supply s you alittle greater distance from the transom to the engine so which you will alsoget little greater overall performance out of it =]

Depends on the vertical legnth of your transom. I'm sure short shaft electric motor would be best for you. Ask a dealer you trust.