Until a very few years ago, when Raymarine introduced their digital radars, they had a potentially lethal fault. I brought this to the attention of their VP, who put me in touch with their top radar guy, who acknowledged it. But, this fault never has made its way into any user warnings that I have heard of. They also said other non-digital radars suffered from the same thing, and that the digital ones don't, but I can't confirm that.
What happened? Although I had used other radars for years (did a lot of singlehanding
for over twenty years, and a radar alarm
was my "other" crewmember), I always tuned them manually, like I was trained to do. The manual for the Raymarine Unit I bought (new) in 2004 dealt with manual tuning, gain, sea clutter, etc, very offhandedly, and was strongly oriented toward the automatic controls. I realize now, that this was probably a marketing
ploy. Anyway, I tested the auto controls, and it was obvious that the radar tunes itself automatically with great accuracy. I could not do better myself. The same was not true of either the gain or the sea clutter controls, but it could take several minutes for this to manifest itself. Manual radar controls usually have levels defined by numbers, which, on my set, were from 0 to 100. On my set, the best gain (tuned for a light background speckle) is somewhere from 76 to 82, depending upon the range setting). Sea clutter would be optimized somewhere between 0 and 30, depending almost entirely upon sea state. Auto controls started on the same range, but it was only a year or so later, when I started getting very suspicious of some missed targets, that I realized that, over a few minutes, gain would settle down to around 50 - 55, which would effectively erase lots of boats, buoys and the occasional island. Yes, island. The automatic Sea Clutter controls were better, but contributed further to degrading targets. In my opinion, it was highly irresponsible of Raymarine to include such a flawed "automatic" system, with the strong implication that the auto setting was all you needed to use. Silly me, I thought that my old training had been superceded by a true improvement in technology.
The aforementioned tech's answer when I asked him about this was. "Sure, all radars, pre-digital, have this fault. I would never use auto settings in any situation where the performance of the radar was important!" How could they sell such a feature?
This was driven home to me in a big way before I discovered this flaw. Some of you may remember either hearing or reading of a catamaran
in the Caribbean 1500
, 2004 edition, that collided with a NOAA weather
buoy about 220 miles off Cape Haterras. It was written up in water
Sailing and Latitude 38, among other places, and there was a fair amount of online chatter about the skipper
who must not have been on watch to make such a mistake. Well, that guy was me, and I was on watch, at the wheel
, looking out ahead on a pitch
black night, well aware that there was a six meter, in diameter, weather
buoy out there somewhere, supposedly with a light flashing every 20 seconds. And, I had my radar on for precisely this reason and, no, I was not singlehanding
. The situation was complicated by the fact that the buoy is anchored in 12,000 feet of water, so its swinging circle was several miles in radius.
Since I had three other crew on board, none with extensive radar experience, I had made the mistake of telling them to just set things on automatic. I had come on watch about a half hour before the collision
, and probably had not thought to re-tune manually. I did not think I needed to. Unfortunately, it also turned out that the light that was supposed to flash every 20 seconds was out, which I am told is highly unlikely as there are several back up lights set up to flash if the one higher up the line fails. Well, I suppose that salt water
is an issue with the electrical
systems on buoys, too, because, all the lights were out, which we confirmed after the collision
Despite the fact that I was looking straight ahead, I did not see the yellow 6 meter in diameter buoy (it is more like a huge floating hockey puck
with various sensors and antennae) until our nav lights flashed on its reflective tape, about a boat length and a half dead ahead. We were doing seven plus knots, under autopilot
. The Raymarine 7000 autopilot
is not backlit, and I had only owned the boat for a few months, so I did not know, instinctively, which button was "standbye"; in the instant before impact, I just leaned as hard as I could on the helm
, and managed to avoid hitting the buoy dead on, but caught it on the bow on the port hull
. This opened a hole right on the stem about two feet measured vertically. That is when I learned how tough a Leopard 45
is ( it would have done much greater damage to most other boats) and how effective the water tight bulkhead is.
Very long story short, (and glossing over the un-requested mayday sent out on our behalf by another boat in the rally, which resulted in attention from a C-130, two USCG cutters, and a helicopter), we did make it back to the Chesapeake with a huge hole but no water into the hull
aft of the collision bulkhead. And, after a $37,000 insurance
claim and many months of a charter
, we were back in business.
For a couple of years, I wracked my brains as to how I could have missed such a buoy on the radar. And, believe me, I was asked about it to no end, as well. My friends, who knew of my singlehanded past and years of radar dependency were particularly incredulous. It was a long time until I finally put two and two together, in a manner that was easily replicated. Quite simply, the automatic settings had blinded the radar, and I was not aware of it. And, I had not bothered to re-tune manually.
We were lucky. No one was hurt, and the boat was repaired. But, how such an "advanced feature" could make its way out of a responsible factory, I do not know.
It is probably true that all older radars share this flaw. Certainly, the old maxim was to always use manual controls. But the manual sure suggests otherwise, and I would be willing to bet that the vast majority of radar users on this forum probably use the automatic controls. And, apparently, this is OK on the digital sets, although I would test very carefully before I would feel comfortable.
But, getting back to the OP, if you get a radar more than a few years old, be sure to learn how to set your controls manually. You will be just fine, if you do. My Raymarine works very nicely that way. As have all the other radars I used previously. Just take the instructions for the automatic settings with a grain of salt