My 17.5 ft. Deep V Smokercraft boat with a 2015 115 hp Mercury 4 stroke pulls hard to starboard, especially when cruising 35+ mph. I have tried adjusting the trim tab in both directions multiple times and adjusted engine trim. I found the best combination to reduce torque pull but still have to turn wheel to Port and hold tight. I have looked online at NFB Steering helms and hydraulic steering systems. I would appreciate feedback from any of you who have experience with these steering systems. I want to minimize cost but also want the torque pull issue corrected for safety and steering fatigue reasons. Thank you for your time and help!

Sounds like your steering hydraulics are malfunctioning.

The hydraulic system may need to be bleed.

You turn the torque tab fin about 15-20 degrees the opposite direction the boat is trying to turn on it's own.

Hydraulic steering shouldn't be feeding back engine propeller torque, you need to bleed out any air that is trapped in the lines.

Rom

I gather from your write up that you don't have either the NFB or hydraulic steering systems, just a direct cable steer.  I have a NFB system on my boat and it does work well and I like it.  There's no way that I'll  say it's as good as a hydraulic system since it still depends on cables.  One thing to consider is that even with NFB, if you don't get your torque tabs sorted out, the cables in the NFB will still be under strain despite the fact that it won't be felt in the steering wheel.

Cable steer on a 2015 115 hp?  Not likely.  I can't imagine anything over 60 without some NFB or power steering.