What Is A Spot Lock GPS Anchor Trolling Motor (And How Does It Work)?

UPDATED 31 JULY 2022

by Eric Bartlett

During the last decade, spot lock trolling motors have taken the recreational fishing world by storm as they have enabled anglers to easily fish in locations that were hard to fish in before, and without having to pay attention to boat control.

In addition to anglers, the spot lock GPS anchor system has been adopted by captains of yachts, skiffs, and many other recreational vessels, in order to help them stay in position easily without dropping a physical anchor.

But what exactly is spot lock, and how does it work? In this article we’ll walk you through the full details, so read on below.

What is spot lock?

Spot lock is a GPS anchor system that controls the autopilot functionality of a trolling motor to maintain the position of a boat within a radius of several feet of a specific set of GPS coordinates.

Because of this ability, spot lock trolling motors can replace a physical anchor by accurately maintaining the position of a boat (and even in relatively strong currents and winds).

Spot lock is most popular among anglers, who use it to position their boat close to fish-holding structures without having to worry about boat control.

Bass fishing professionals especially love this feature, since it enables them to spend more time actively fishing, while wasting less time on boat control. 

The term ‘spot lock’ was originally coined by Minn Kota, who used it for their GPS trolling motor anchor.

And since Minn Kota were the first to introduce GPS technology to trolling motors with their i-Pilot system in 2009, the term ‘spot lock’ has since become widely adopted as a synonym for all types of GPS anchor trolling motor system.

If you’re currently in the market for a new spot lock trolling motor, check out our article on what are the least expensive spot lock trolling motors?

How does spot lock work? 

Spot lock uses GPS signaling to compare the GPS coordinates of a desired location to the actual GPS coordinates it measures at any given moment.

If the spot lock algorithm detects a discrepancy in GPS coordinates between the desired and actual location, it activates the trolling motor autopilot, and controls it to move the boat back into the desired location.

This process is repeated over and over again, with the result that the boat is kept within a 3 to 6 foot radius of the desired location, without any active input from the angler.

This has revolutionized sportfishing since it frees up the angler to focus one hundred percent on fishing, without having to pay attention to boat control. 

One way to input the desired GPS coordinates is to hit the spot lock button (which has an anchor icon on it) at the moment when the boat is exactly on top of that location.

The spot lock system then remembers these coordinates, and will direct the motor to actively keep you in that location.

Another way to input GPS coordinates that you want to target is by networking your spot lock trolling motor with a compatible mapping device, and then instructing the spot lock system to take you to a specific GPS waypoint on the map.

How accurate is spot lock?

If set up correctly, a spot lock trolling motor can maintain the position of a boat with an accuracy of 3 to 6 feet distance from a specific GPS location, assuming normal wind and current conditions. 

However, keep in mind that it’s important to calibrate your spot lock correctly in order to achieve this level of accuracy, and that you also need to choose a trolling motor with the right amount of thrust for the size of your boat.

An underpowered trolling motor used on a big boat is unable to maintain an accurate position, especially if you’re dealing with a strong current or wind.

Bass boats are often sold with underpowered trolling motors, so this is something to keep in mind when you make your purchase. 

On the other hand, if your trolling motor is too powerful for the size of your boat, spot lock will tend to overcorrect, which also results in lower accuracy.

When did spot lock come out?

Minn Kota first came out with spot lock in 2009, when they introduced i-Pilot for the first time. But back then the ability of i-Pilot to keep a boat in one place wasn’t highly accurate, so it wasn’t widely adopted by the fishing community right away.

While some bass pros already started using spot lock back in 2010, the big breakthrough came in November 2016, when Minn Kota launched the improved i-Pilot system, which has a much higher level of accuracy compared to the previous version.

Nowadays it’s hard to find any bass pros (or walleye pros for that matter) who don’t use spot lock, and many amateur anglers use it as a standard feature as well.

Do you need GPS for spot lock?

Yes, you need GPS in order for spot lock to work, but all spot lock trolling motors come with built-in GPS, so you don’t have to add GPS separately.

In fact, even if you retrofit a trolling motor with spot lock functionality by adding i-Pilot to it, you don’t have to worry about GPS, since the i-Pilot head has GPS built into it.

However, if you have another device on your boat with GPS (such as a fish finder with mapping functionality), you may be able to network that with the spot lock trolling motor, depending on their compatibility.

And if you already have a complete boat electronics system, it’s worth checking out which spot lock trolling motors are compatible with your existing system before you buy.

Do you need a fish finder for spot lock?

No, you don’t need a fish finder to use spot lock, since a spot lock trolling motor comes with its own built-in GPS system, which can effectively keep you in a specific spot without the help of a fish finder.

But with that being said, a fish finder can add a lot of extra functionalities to a spot lock trolling motor, especially if it has mapping capabilities.

For example, if you see a school of fish on your fish finder, you can create a waypoint on your lake map at that position, and then instruct your spot lock to keep you at that location while you fish.

Also, you can use a lake map to tell the spot lock exactly where you want to go, and it will take you there.

Alternatively, you can use a lake map to get the trolling motor to navigate along contour lines at a specific depth, which is a game changer for trolling.

Can you add spot lock to a trolling motor?

Yes, you can retrofit some trolling motors with spot lock functionality, but this option is not available for all of them. In the case of Minn Kota, the following trolling motors can be retrofitted with spot lock by using an i-Pilot kit:

  • Ulterra
  • Riptide Ulterra
  • Terrova
  • Riptide Terrova
  • PowerDrive
  • Riptide PowerDrive

Keep in mind that even when dealing with these Minn Kota lineups, not all models are spot lock compatible, and which ones are depends on the year they were built. To check the latest compatibility chart by Minn Kota, click here.

Also, if you do have a Minn Kota model that is compatible with an i-Pilot add-on, you’ll have to choose between different versions of the kit, depending on whether your trolling motor is bluetooth compatible or not. 

What is spot lock jog?

Spot lock jog is a functionality of i-Pilot that allows you to move 5 feet in any compass direction by pressing a button.

In order to do this, it uses a heading sensor that functions as a digital compass, and determines the direction in which to move the boat. 

Spot lock jog is a great feature if you want to follow a school of fish on your fish finder, and you notice them moving in a specific direction.

You can also use it to move along a fish-holding structure, such as a drop off or ledge, and thereby systematically dissect it in search of fish.

Does MotorGuide have spot lock?

Yes, MotorGuide trolling motors have spot lock, but their version is called ‘GPS pinpoint.’ The term ‘spot lock’ is used specifically for Minn Kota trolling motors, while other companies use similar terms for their GPS anchor systems. 

For example, Garmin and Lowrance use the term ‘anchor lock’ on their trolling motors, MotorGuide calls it ‘GPS pinpoint,’ and Rhodan Marine uses the term ‘GPS anchor.’

These slightly different terms actually all refer to the same thing – a GPS lock trolling motor.

Another thing to keep in mind is that you may want to choose a brand of spot lock trolling motor that is compatible with your existing boat electronics.

Conclusion

Spot lock trolling motors have been a game changer for the recreational fishing world since they were introduced more than a decade ago.

If you have the opportunity to try one out on your own boat, I highly recommend that you check it out.