January/February 2006 Volume 1, Issue 5
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®2006 Tsunami Fishing Systems

  
Look Mom! No Hands!

One of the gadgets we added to Toy Boat 2 was a Simrad AP12R autopilot. Luxury? Or irreplaceable tool?
Background  |  Installation  |  Commissioning  |  Peformance  |  Safety&Reliability  |  Summary
Performance
Here's how the unit performed in the field (keep in mind that this also reflects a couple of years of real world experience as well).
  • Manual override  - Required moderately large effort to turn the wheel while the AP12R was in control. We suppose in a panic situation, you probably wouldn't even notice.

  • Holding a steady course - The unit has always done well when told to hold a steady course from Point A to Point B. We tried several different gain settings (which controls how fast the unit tries to correct course errors), to see how it affected operation. We ultimately settled on (the factory default settings + 2) as giving the best results for TB2.

  • Course navigation - Also good, once the gain was set and the compass properly compensated.

  • Hunting for a heading - We tried a couple of scenarios where the bow was pointed 180 degrees away from a waypoint when we told the AP12R to navigate to the waypoint. With the boat running forward at about 3 mph, the AP12R had a hard time, wildly swing the boat one way, then the other. It would eventually settle in to the right heading, but it was bit unnerving to see the steering wheel go fully lock-to-lock back and forth. It probably would have converged on a heading sooner if we had either been travelling faster, or been pointed more directly towards the waypoint.

  • Spin-right - After about 12 months we started having occasional problems with the AP12R suddenly swinging the boat into a hard turn to starboard, for no apparent reason. The first time this happened was immediately after impacting a big swell, so we assumed the fluxgate compass had spun wildly to starboard after impact, causing the AP12R to try to compensate.

    Later on, however, it started occasionally happening on its own, for no apparent reason. As time wore on, it started to happen more frequently. It always occured late in the day, and several times we had to disconnect the AP12R and drive home by hand.

    About this time we also discovered an issue with the solenoids in the console. Solenoids normally don't use a lot of current, but they have to have current flowing to stay in a certain position. Thus, when the solenoids were energized, they generated a magnetic field which caused deviation in the fluxgate compass. As noted earlier, it was enough to cause the fluxgate to swing +10 degrees.

    What do you think happens when a solenoid's mechanism gets mechanically stuck in one position? It draws a lot of current to try and move the armature. The more current, the stronger the magnetic field. So...you can imagine what happened when I powered up the solenoids and one or more of them were stuck. The massive current draw caused a large magnetic pulse, which caused the AP12R to pull into a hard right turn. The solenoids also got hot enough to flash off the residue from some Corrosion Block I had sprayed on the night before, creating a large white cloud of smoke, but that's another story...

    Bottom line - it turns out that there could have been any number of factors causing this problem. Ultimately, it turns out that we caused the problem by operating the autopilot in a particular manner. See the next section "Safety&Reliability" for a more detailed discussion.
Benefits
  • Trolling setup - Toy Boat 2 does not track very well at low speeds. This made setting up trolling spreads difficult, especially when fishing solo. Now it's a piece of cake. Set the AP12R on a course, throttle up to 3-4 mph, then set out the trolling lines.

    courtesy Sid Wales


  • Not having to steer while using binoculars - In a small boat, keeping binoculars stable can be difficult. An autopilot allows us to use two hands to hold the binoculars

  • Rigging gear while running or trolling - Similar to the observations about binoculars, the autopilot makes it possible to rig tackle and gear while the boat is moving. Of course, it's still imperative that you keep a close watch for obstructions and other vessels.

  • Fuel usage - It's really surprising how hard it is to steer a straight course over any kind of distance. We don't know if we're typical, but without the AP12R we are constantly drifting off to starboard. This effectively increases the distance we travel, with the associated increase in fuel usage and lost time.

  • Fatigue, running in rough water - It's also surprising how fatiguing it is to drive the boat over a long distance, especially in rough water. The AP12R eliminates the need to steer, so we can relax in smooth waters, or focus on hanging on for dear life and tweaking the throttle when it's rough.

 

 
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