You ever get twisted around?

It's good to have a recognizable landmark to orient one's self; in this case Mt. Diablo:

Wxx3 said:

From the get go, my brain put the office on the north side, so upon exit, i turned right instead of left and then proceeded to NOT ignore, but to rationalize away, why NOTHING ELSE, was where it should have been.

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Happens to me sometimes getting off a subway.

Some of the canyons on Lake Powell are so twistty, so narrow and so high, it is easy to get bent in half real quick. You can see daylight above but no sun. A lot of places, the only way out is in reverse. I made a wrong turn in a maze. Everything closed in......

When boating, I don't get lost or turned around.....but I have seen some interesting places that I hadn't originally planned to go to.

As I get older, I find my memory plays tricks. Traveling the second time down the AICW, 2 years after the first, and in the opposite direction, things weren't as I remembered them. Some sections were much shorter than expected. Some didn't look anything like what I expected from the opposite direction. There were some spots that I vividly remember and never saw. Then there were the sections where the waterway was moved to a different county in the last 2 years.

That's when I start second guessing myself. Did I miss a turn? Have to keep checking for yellow triangles and squares (ICW markers on navigation aids).

Ted

Once it wasn't me but my crew of two buddies who had the helm for a few hours at night. We were returning from an offshore fishing trip, with the understanding that I was to be awakened when we were two hours off, or if we got within a specified CPA/TCPA of another vessel. That would put me at the helm in the more difficult waters. All they had to do was keep watch, the auto pilot would do the rest. My buddies saw the lights of Palos Verdes and that gave them a good sense of position that, for whatever reason, neither the chart plotter nor the radar could provide. Being good guys, they decided to let me sleep a bit longer.

In any event, I was suddenly awoken by their screams of "Palos Verdes is moving!". Apparently, a freighter had managed to come between them and Palos Verdes. From that point they mistook the frieghter's lights for those of Palos Verdes. When they realized that the autopilot was taking them closer toward Palos Verdes than it should, they turned to port, repeatedly. Finally, it dawned on them that Palos Verdes was moving.

Pucker factor increases for about 15 seconds every 2-3 hours when travelling. I will forget to turn the page on the chart and suddenly realize the marks on the chart and the GPS disagree. Turn pages and all is right with the world and calm returns.

In my Bayliner I was used to traveling at 24+ mph, and everything was where it was supposed to be. When I switched to the Willard I kept having "deja vu" moments, where every bay and point looked like the one I passed before. Then I realized I was going so slow it WAS the same place I saw before There certainly is a learning curve to traveling at 6 knots...

Based on many posts....hope many of you never get caught in dense fog at night in a good chop and restricted waters or am amazed that you have never lost it in those conditions.

When you lose track of where you are, but have sight of objects and basic up and down, is no big deal...true disorientation can be a killer if you don't stay proficient with your gear.

Obviously PS knows. And I agree 100%. Like him I have been "lost" lots of times. Slow to a crawl, take stock, get your bearings (compass and chart) befor continuing on your way. Lots of times I have been going the exact opposite direction I thought I was and rationalized everything I saw, even though I had seen it many times befor. Even changed the charts from north up to course up trying to figure it out. The old reliable compass was even wrong for some reason. I was obviously right, just couldnt figure out why all my input was wrong.

PS,

I've been there in thick fog, absolutely calm conditions with bright sun illuminating the fog. I was traveling on autopilot and nothing seemed right. I thought I was looking at a rock on the port bow, but no radar return, and nothing on the chart. I corrected for it anyway to starboard, and it was still there. I'm running at maybe 4 knots and still nothing is as it should be. I never did discover what I was seeing and confusing me, but it never got any closer and when we got out of the fog about 5 minutes later the rock was gone. With no visual references vertigo was taking effect if I didn't look at the surface of the water near the boat.

I've had the same experience skiing in the fog when you can see your skis but not the snow or slope below you. I have fallen over with exactly zero forward speed because I thought I was leaning into the slope and the ground was really flat. The lack of a visual reference takes away normal feelings of balance. We call it skiing in the milk bowl.

Tom

Twice before gps. Once in the Delaware Bay during a squall so bad we could not see the bow of the boat, Once in the Chesapeake taking the inside route north from Chrisfield and missed the turn into the bay itself. But the strangest was this past summer fishing the mouth of the Delaware Bay in an area called "The Rips" where the water shoals to 2-3' very quickly. That's when we found that gps is not exact. It was time to go after another "successful" day of catching Skates and Dogfish. The gps had us on the north side of the rips but we were actually 30' away on the south side. Luckily we were using the Parker with the outboard that day. Had to raise it almost out of the water to get by. If we were in the Mainship we would never have made it to the really shallow part.
John

Greetings,
Mr. j. " That's when we found that gps is not exact." I think everyone needs to keep that in mind.

GPS is sure a lot more exact now than when it was first made available to the public. No more induced random error for security purposes.

With a clear view of the sky and a decent receiver, I am continually amazed at how exact they really are.

Believe GPS is more accurate than charts. For instance, electronic charts showed me on the shore of the upper Petaluma River/slough (west of Lakeville) while actually being in the middle of the channel. There was about a 50-foot difference.

Further up the river where charts were on the mark:

As we were hand steering across the Gulf of Mexico a few weeks ago, one of my crew was on helm duty, and ended up 180 degrees of the course line. He steered that course for a while before he realized something was wrong and called for help as he was confused and feeling vertigo. I was asleep, so the third crew member who was close by got things turned around. This happened about 1:00 am.

Conall

The GPS is accurate...it is the charts that aren't. Absolutely many small thoroghfares, creeks , etc aren't exactly "on"...but figure many are still on charts when they were measured by tape and transit...buy guys trudging through the swamp on foot.


The rips in Delaware Bay are a great example. I have fished them 100s of times and I would say every chart I have and some of the electronic charts have completely different representations of them. The only ones that are similar are the fishing charts that just mimic the NOAA ones.They are just large sand waves for the most part and change all the time...so I'm not sure what charts out there have really the best representation of them.


When visual clues are lost...the mind plays all sorts of tricks on you. Throw in vertigo and special orientation is under constant attack. Even with visual, optical illusions can kill you. A good example was in Biscayne Bay climbing out after a water approach at night...the nav lights of two airplanes diverging (one plane was taking off from Miami Int and another was on downwind) appeared to be nav lights of a single plane coming at us so close and fast, the other pilot cut power, banked and dove just a few hundred feet off the water. I saw the same thing which is unusual for optical illusions but possible. We just barely cleared the water and it took WAYYYYYY too long for both of us to get that visual out of our heads and figure out what it was. Our eyes saw the lights diverging but our minds painted in a small airplane between them because it was dark and we always expected the unexpected.


A great example of all of this is when you are sitting at a red light. You are looking down, out of the corner of your eye you see the car next to you creeping forward. You think you are rolling backward but in reality, you are still...it is just the other people moving for the green light. It is a paradigm shift that shows your senses can be easily overridden and like I posted before...only training and experience (or luck) will get you though the tough ones.

GPS has become so reliable and accurate it's hard for me to imagine moving a boat without one. When folks see their chartplotter not showing their exact position in relation to their surroundings it's generally the charts within the plotter that are not exactly right. You have probably noticed this in some narrow channels and rivers where the plotter will show the boat on the shoreline when you are actually in the middle of the river or channel. The charts within the plotter are derived from govt data some of which have not been updated in many years. It amazes me that some of these older govt charts are as accurate as they are.

Spatial Disorientation is not getting lost but a complete loss of orientation. It can mean not knowing which way is up or down but can also mean a complete loss of your sense of direction. This happened to me many years ago when flying co-pilot for a regional airline. I was preparing to fly an approach to an airport in IFR conditions when unknown to me the Capt. changed the frequency of the nav aid (VOR) I was using without telling me. I was flying on instruments and when I looked back at the Nav aid (VOR) nothing made sense. He had changed the frequency from the VOR to the ILS, which is the nav aid used to guide the airplane to the runway in both azimuth and elevation. It was necessary to change the freq but I was still navigating using the VOR and not ready to switch over. We resolved the issue but today this would not happen. Coordination between crew members is much better established.

While it is common to see errors on the chart plotter map where you're closer to land than you actually are, the navigation itself is very accurate. When I make a mistake, it's usually misinterpreting what I think I see. I do very well in the fog or at night as there is less to misinterpret and I rely more on the radar and plotter. A good example is returning at night to Ocean City, MD. Try to find the seabouy with it's blinking red light against a sea of lights from the amusement park behind it. It's very difficult until you almost on top of it. Fortunately the plotter and radar don't have that problem and it's not hard to spot it when your heading directly toward it. In unfamiliar areas, I now find myself taking reference points from the plotter / radar and matching them to what I see, as opposed to the other way around.

Ted

Good point Ted...the more you use your tools the more they are an extension of your senses. I would guess those on the water all the time can relate.

I was taught that in navigation you are supposed to know where you are...navigation is really the art of confirming your "guess".

Whether a glance out the window or the glance at the RADAR gives you the info you need, the source isn't important. But you can see when it might be.

Greetings,
So the GPS is right and the chart is wrong? Golly, what use is it then if the "blip" where you are, on the GPS, is on shore? So take away the incorrect chart and you're left with a "blip" overlaid onto a blank screen??????

Lucy...You got some 'splainin' to do.

RT Firefly said:

Greetings,
So the GPS is right and the chart is wrong? Golly, what use is it then if the "blip" where you are, on the GPS, is on shore? So take away the incorrect chart and you're left with a "blip" overlaid onto a blank screen??????

Lucy...You got some 'splainin' to do.

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Your GPS still gives you all kinds of very accurate information that is useful. The only thing to remember is that the charts, and therefore the plotter on with your GPS information is overlaid, are not 100% accurate.

I am fortunate that most of the waters in which I travel are very well charted and there are few natural forces that are changing the landscape very quickly. Even so, I try to always remind myself that what I see on the chart plotter is someones best representation of what is in the real world, but it is NOT real. Still have to look out the window.

I swear I din't take it up there !

Once you have a track set, the GPS repeats it perfectly. I have run in the dark to pick up my shrimp pots many times "on the track" not even able to see shore. I would swear the GPS is accurate to that track within a couple of feet. The charts on the other hand are often off by several hundred yards. I don't go poking around in the dark using the chart plotter as my guide. I kick on the radar and anchor very conservatively when sneaking into an anchorage I don't have a track into.

As said above, once your GPS has laid down a track, it doesn't matter if some of it is on land or otherwise innacurate, it is very repeatable.

It is also easy to get used to the chart being off, by some distance, but mostly the same distance in the same direction. This is due to the datum being off, so a new track can be laid down, trusting the items on the chart to be correctly placed in relation to the inaccurate datum.

The most extreme example of this that I have experienced was while cruising in Turkey, on charts done by Beaufort about 200 years ago All the harbours were correctly drawn, but related to a datum that was off by as much as a nautical mile. This made things exciting for the navigator, below where he had no windows, while I, at the wheel, could see where I was and what else was around us. My view was a bit better for keeping us in the water, while taking a narrow passage out of harbour.