Humminbird 581i HD DI

[Jethro]

Does anyone else here use this unit? I just bought it because it was the only one in my budget that had GPS, but with my first use I am disappointed. The problem is the GPS at trolling speed. Really the biggest reason I needed GPS is because I like to troll, and of course I need to know my exact speed. The speed jumps around so much when below 3mph that it's just about useless for this purpose. I have a 20 year old Garmin GPS IV that I have used forever that is dead on. How can a new unit, even at a low pricepoint like this be so inaccurate? Just want to share my experiences. Everything else is great, a huge upgrade from my Piranha Max portable, the sonar is awesome, but it looks like I will still be buying double A batteries in bulk for my old Garmin for trolling purposes.

Does anyone with one of Humminbirds better units, maybe a 688ci HD DI, have some input on the GPS accuracy at trolling speeds? Don't figure I can return this to BPS as I installed it on my boat, but maybe I can sell it. It would be an awesome unit for someone that doesn't troll for coldwater species and is on a budget.

[mwoj43]

I have a humminbird 597 hddi. GPS work great. You have to consider, GPS reads speed over ground, If you have a current, waves, head wind or tail wind, it affects trolling speed greatly

[Jethro]

Yeah, speed over ground. It's not accurate at all. Sitting still in the parking lot it jumps from 0-4mph all the time. My small handheld unit is accurate but the Humminbird jumps all over the place. A 597 is a much nicer unit and probably has a better internal GPS.

[Mac Attack]

Have you contacted Humminbird?
Maybe there's a software upgrade for the unit to fix things.
Lowrance is constantly offering software upgrades for their units on their website.
Just a thought.

Here's a link to the FAQ page on their website.

http://www.humminbird.com/support/faq/

There is one there about software upgrades and it says you need to register and create an account.
I didn't read any further, but you should really contact them.

Good luck.

[Jethro]

Thanks for the link, I'll give it a shot. I'm not hopeful as I have seen this same issue from other people and their reviews online, but it is worth a shot.