With that size boat 36v is really the only option if your want to fight winds and fish offshore!

I went to the 112 pound fortrex from 70 pounds best thing I did cost me more but no issues now

I went from a Maxxum 70 to fortrex 80 and see a huge difference.

I took my older 74lb Mk maxxum off my 461 ranger and put it on my 16 ft duckboat...replaced it on my bass boat with an 80lb maxxum and I really can't tell the difference between 74lb and 80lb.....maybe there is a slight difference between 70lb and 80lb but as several others have said...get you a 112lb thrust MK and you will be much happier....

you will need a 101 for a boat that size, especially with 3 people.

Might as well go big and be done with it. I run a 36v 101 on my Z7. It's more than enough in the wind

I made comment based on OP. Every comment on here is good. It's true, if you want to eliminate trolling motor weakness, go big. Add 3rd battery, extra bank on charging, 36v TM with 112#'s. That's a BIG boat to move in wind & 3 men & gear. 3 batteries will last longer than pulling the guts out of 2 on a 24v system. Good luck & I hope you find good deals on what you need. You can always turn a Big TM down but can't turn up a smaller one that's maxed out.

Sell that boat and buy a Yak'. Call Jones Trolling motor service,over in Texarkana Ar. John, sells ands services all that has been mentioned.

I guess I'm going to bite the proverbial bullet and go 36v. I'm tired of messing with a trolling motor that is too weak.

Thanks for all of the help/suggestions!

It isn't like you are using 80# thrust every time you use the motor, but a 36v allows you to not have to run the trolling motor as hard all the time. Make the 36v system happen.

I had a Maxxum 80# unit at one time and I was almost never under 40% power and regularly at 70-80%. Assuming the batteries are healthy, a 36v 101# thrust will make a 21' boat jump at even 50%. That is a lot of subjective talk, but you will never regret a more powerful TM.

I have a TR21 with a 80lb 24volt.... It works fine until the wind blows. I definitely need a 36v

go to 101 at least,.
my FX21 handles great in the wind

I'll go out on a limb and give you a different answer. The 70 Edge is a 5 speed trolling motor whereas the 80 Foretrex is variable speed. I had a 70 Edge on a previous boat. Skeeter loves to put those piece of junk Edge motors on their smaller boats. Speed 3 and 4 were not enough to fight the wind. Speed 5 was too strong to control the foot pedal and would drain batteries in about an hour. The Foretrex 80 uses far less battery, is a true variable speed and is significantly stronger. If you can't manage a 36 volt system, you will still see a huge difference with the 80 Foretrex over the 70 Edge.

My Skeeter is only a 190zx so it is smaller but I went from the 70 Edge to the 80 Fortrex and saw a big difference. Mainly because the Fortrex is a work horse, much more stable and solid.