You don 't need much wind when you are on a jonboat to experience manueverability and wind drift issues, I tell you this for your own good.
My boat even though a 12 ft is a Mexican built jonboat with thicker and heavier aluminum than most jonboats I 've seen in the states ( my 12 ft weights about the same than a 14 fter ) and it still drifts fast with a little wind ( around 5 MPH ) the windier it gets the more thrust you need, get into the 10 MPH and with 40 lbs in that boat you 'll drift like a kite.
Two things are certain with TMs:
1.- You can never have "too much" thrust
2.- The shaft is never "too long".
Bassmaster6 says: "unless there is extreme winds it pulls my boat along with no problem at all"
He never been around my home lake when there 's "extreme" wind and the waves hit the 3-4 ft mark . When I say "I should have purchased at least a 50 pounder" I know what I 'm talking about.
There 's also a point to take in consideration, the smaller your TM the more battery you wear because you 'll have to run on a higher speed for more time to maintain your position or to manuever to contrarest the effect of the wind drift, higher speed ----> your battery runs out of juice a lot faster, I 've juiced out my TM battery more than once when it gets windy and the fun has to end earlier cuz we ran out of battery. >
Also, I recommend you get an extension arm for your TM, normally the extension handle in the TM is not long enough and it always points in the same direction ( straight ahead ), try a day of manuevering the TM you standing up and having to lean down to grab the handle and you 'll know what back pain at the end of the day is all about.
I puchased an extension arm called Stiff Arm ( I found it at Academy Sports ), it clamps down on the TM shaft just below the head of the TM and you can lift or lower the arm so you can reach it easily, cost a few bucks and it 's one of those things that makes your life a lot easier, best money ever spend.