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Electronically Aided Collisions


What happens when you let a box of diodes, transistors, and microprocessors assume command of your boat, even for a minute? Just about every accident you can think of.

What happens when you let a box of diodes, transistors, and microprocessors assume command of your boat, even for a minute?

Just about every accident you can think of, from groundings to collisions.

According to reports, this boat (not insured by BoatUS) was traveling in the ICW under autopilot when it suddenly veered and slammed into the bank. Several people were injured, but none seriously. The incident underscores the need for caution when relying on electronics in close quarters and illustrates why a human needs to be vigilant at all times.

Over the years, Seaworthy has published articles that had more to do with common sense (don’t drive drunk, don’t go boating in a hurricane, avoid depths shallower than your keel, etc.) than with boating skills. Recently the Coast Guard identified yet another “common sense” topic: Electronically Aided Collisions (EACs), which occur when a boat’s skipper puts too much faith in the boat’s electronics. An EAC can be as simple as a grounding that occurs when an autopilot strays off course or a collision that occurs because the boat’s skipper is more involved in fiddling with a GPS than paying attention to where the boat is headed. In most cases, Rule Five of the COLREGS was ignored: “…every vessel shall at all times maintain a proper lookout by sight and hearing as well as by all available means.”

The reason for the increase in EAC’s has to do with the proliferation of affordable marine electronics — GPS chartplotters, radar, and autopilots — that are finding their way onto more and more boats. Seaworthy has analyzed some of the claims and even spoken to a few willing, if embarrassed, boaters. The causes of EAC’s are many, but tend to be grouped into three areas.

The Video Game Syndrome

A skipper in New York, who recently spent a lot of money on an integrated navigation system for his 43-foot cruiser, told Seaworthy, “My wife used to refer to the boat’s nav system as my $10,000 video game. After I bent both props and rudders on some rocks while I was showing her how the system worked, she started calling it my $20,000 video game.”

Manufacturers design navigation equipment to be easy to use, and some of them are downright fun to use. Some electronic devices even have digital joysticks — a device first used in video games. Interactive displays can show data from charts, GPS, radar, depth, speed and wind instruments, and even television. Some screens have moving 3-D icons of the operator’s boat with chart, bathymetric, and radar overlays, and even sounds. Ironically, skippers who become too involved in their navigation electronics might need to recruit a second person to act as a lookout; operators can get so intent watching the colorful “video voyage” that it’s easy to forget to look up. Depth sounders, knotmeters, wind indicator instruments, engine gauges, and a VHF, can all compete for the skipper’s attention.

Limitations, Inaccuracies, and Failures in Electronic Equipment

The accuracy of current GPS’s is startling — most manufacturers claim to be able to locate your position to within about 10 feet when using WAAS (Wide Area Augmentation System) GPS’s. In fact, they are so accurate that several claims have been made when skippers set a waypoint to a buoy or marker — and were surprised when they hit it. The amazing accuracy of GPS sometimes lures boaters to be complacent — what can go wrong if you know within a few feet where you are? But there is no guarantee from manufacturers or the Department of Defense, who operates the GPS system, that GPS’s will have, or continue to have, that accuracy.

According to a spokesman for the Department of Defense, every once in a while a GPS satellite malfunctions and gives inaccurate data that might take a few minutes to correct — a few minutes that could ruin your day if you’re relying on a GPS to steer your boat. Certain atmospheric factors and other sources of error can also affect the accuracy of GPS receivers, as can the number of satellites visible. The GPS datum and chart datum have to agree and even if they do, there still may be problems. A Seaworthy editor, to cite but one example, was taking a friend’s trawler south in the ICW when he noticed the boat’s chartplotter showed the boat to be about 200 feet inland. The trawler was equipped with an integrated system that relied on GPS input — the autopilot, chartplotter, and radar used the data. He didn’t know when the inaccuracy began, but he said he would have found out quickly if he had been using his GPS-integrated autopilot to steer the boat. The lesson: Electronics are not fool-proof — rely on your eyes first, then your electronics — if they don’t agree, stop until you’ve figured out why.

Other problems happen sometimes when electronic devices simply fail: A 30-foot sailboat was motoring alongside a pier when the belt on the autopilot broke and the boat suddenly veered into a pier at six knots (Claim #011384). The man was alone on the boat, trying to tie up his mainsail and was thrown into the cockpit, injuring his ankle. With all the potential pitfalls, it’s a bad idea to trust your boat — and your body — to any electronic gizmo.

Allowing the Boat’s Electronics to Assume Command

The owner of a 37-foot powerboat set a waypoint and left an experienced friend at the helm while he went below to look at the chart to find the nearest fuel dock. The wind was calm and the seas were flat when the boat, with many guests aboard, headed for a rendezvous on Lake Michigan. With nearly unlimited visibility, how is it possible then that the boat ran over a 19-foot fishing boat, throwing three friends into the water and killing one (Claim #008359)? In the claim, the boat was on autopilot when it ran over the stern of the fishing boat. The blame can’t be laid on the autopilot, which was doing exactly what it was designed for — keeping a steady course. It’s possible the droning of the engines affected the lookout’s attention. It’s also possible that the motion of the boat or the rise of the bow prevented the lookout from seeing the four men, all of whom were waving their arms and shouting. The man at the helm couldn’t explain why he didn’t see them; according to one of the men in the small boat, he’d been heading towards them for a couple of miles. The owner of the larger boat, who had set the autopilot and was navigating, was convicted in the death of the lost fisherman.

Unfortunately, this claim is not the only one of its kind. Three years ago a boater was convicted of running down a fishing boat off the coast of New Jersey and killing two of the three men aboard. The boat was also on autopilot (Claim #2000377).

Most accidents aren’t nearly so serious. A more typical autopilot mishap was related to Seaworthy by Wilbur Tapscott, a member in California who wrote about his temporary lapse in common sense: “I was sitting happily on the flybridge with no one else aboard. I was headed to a yacht club and noticed I was flying the wrong burgee; protocol overrode clear thinking and I went forward. The wind had been picking up and the boat topped a wave and swung 90 degrees and ran right into the river bank.”

Other claims started with a quick trip below to fetch a camera (Claim #0107141), binoculars (Claim #0003658), or to find a chart (Claim #0305698), and ended with a grounding or collision. “I was only down for a minute or two,” was the explanation in most cases. But a boat traveling at 30 knots will travel a mile in just two minutes. At the risk of stating the obvious, a boat needs to be under human supervision at all times; not only is it common sense, it’s the law.

BoatUS Editors

Contributor, BoatUS Magazine