Expert: Richard Andrae - 12/14/2004

Question
I hope you can help with this...i need a trolling motor for my 17.5' jon boat.  Most people recommend a 50 lb thrust or so..but is that for a fiberglass boat??  Will a 40 lb. be strong enough for a alumminum boat of that size.

some specs:

17.5' alluminum, center console, typically 1-3 people, fishing poles, tackle, ice chest (with ice)

Answer
-Joel
 
Sounds good to me.  I am assuming you are speaking of an electric motor since you are speaking in terms of thrust.
It really comes down to just how fast you want to go when trolling.  You do not say where or for what species you will be trolling.  Here is some typical speeds related to species I troll for.  This should help you determine how much power you would need.

Stiped bass - 2 to 3 mph
Blufish - 4 to 5 mph
Tuna and related species - 7 to 8 mph

Hope this of some help.  As you can see, with striped bass you could probably troll with an even smaller kicker, but if you intended to troll for tuna, even the largest electric might not be enough.

Have you considered a gas engine?  Something in the 6 to 10 HP range?  It would let you troll and at the same time give you the extra security and safety of a second engine. With the electric, battery power is a consideration and you might not want the extra weight of the battery or batteries needed for a day of trolling.

-Rich