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HVVega 01-30-2011 06:03 AM

Near misses and other not so funny stories
 
This thread is a spin-off from another thread about people relying on electronics to keep watch for them rather than doing it in a seaman like manner. Well maybe that is a bit over simplified, but you get the idea. It came out in that thread that it would be a good idea to have a thread about near misses and other "exciting" things that happen on the high seas. I will start it with this "cute" little pair of stories that happened just after the great Sumatra tsunami. We had about 28 tons of food and medical supplies on board and were on our way to the west coast of Sumatra.

05:20 The sky was just getting light when there was an urgent call from the watch on deck. I felt the boat start to turn hard. We rushed up just in time to see an entire house roof complete with chickens, a dog, and a duck go bye on our port side. The radar had seen nothing. Thanked the lad on watch for a job well done. Went back to sleep.

17:10 Was on watch when I saw something large and dark low in the water directly ahead of us. Checked the radar but saw nothing there at all. Turned 30 degrees port "just in case" Glad I did. It was a mostly submerged shipping container. We cleared it by about 35 meters.

The idea behind this post is to make it clear why there should always be someone on deck keeping a proper watch. Now what stories do you have to trade with us maties?

Yorksailor 01-30-2011 08:22 AM

Back to electronics...I am on a mooring ball 200 yds off Puerto Morelos in Mexico. I can smell the bacon cooking in the restaurant.

My chart plotter shows me 880 yds further east on the other side of the reef. When I passed that reef sailing to the buoyed channel the plotter showed me 900 yds from the reef...

#1 Eyeball showed me to be exactly 100 yds from the reef. In the dark I would not have been within a mile of it and I would have hove-to in deep water until daylight.

I am using Navionics and Raymarine plotter but it is not the plotter that is wrong... it knows where I am... but the fact that the original chart is just off by 800 yds! Which is why, like Vega, I only trust the #1 eyeball.

Phil a Neo-Luddite

Neo-Luddism - Wikipedia, the free encyclopedia

Flybyknight 02-01-2011 07:13 AM

Quote:

Originally Posted by Yorksailor (Post 692531)
I am using Navionics and Raymarine plotter but it is not the plotter that is wrong... it knows where I am... but the fact that the original chart is just off by 800 yds! Which is why, like Vega, I only trust the #1 eyeball.

Phil a Neo-Luddite

Now that's terrifying!

Dick

HVVega 02-01-2011 07:41 AM

Chart positions et al
 
You get used to it mate. We deliver to one island that is 4.72 nm SSW of its charted position and that is not the worst we have found by a long straw.the further off the beaten path you go the greater the error seems to become. That is why God gave us the old Mk-1 eyeball and a brain.

Boasun 02-01-2011 09:25 AM

Yes the brain is a required Navigation Tool. :D

labatt 02-01-2011 10:23 AM

Map inaccuracies are not that uncommon, even in the US. Navionics positioning on the Champlain Canal is off (see the picture below). When we were going down the ICW we were often shown on land. I'd hate to navigate the ICW by Chartplotter alone. We tried to do this at one point in a dense fog and almost ended up on shore.

http://labatt.dandd.com/d/844-5/IMG_0838.JPG

P424 02-01-2011 11:20 AM

A lot of the old Bahamas charts were old English charts and some islands are way off. Then again I have run the ICW from Vero to Cocoa Florida at night and the plotter was dead on. I have seen an area in the Abaco's that depths were miss-marked and showed over 10 ft and actually on another up to date chart was more like 5-6ft. Dont trust verify always.

Boasun 02-01-2011 04:25 PM

When I ran the ICW in Louisana & Texas, during restricted visibility. I use the Radar, Fathometer and the tops of the bushes & trees to determine where the channel is at. And use the chart plotter to see what twist or turn is coming up or in. Freaking GPS has had me a couple hundred yards to one side or the other and nowhere near the water.

Besides, Near misses are lessons learned and not to be forgotten.

Faster 02-01-2011 04:38 PM

Pre-GPS days here.....

Early in our sailing we were in Victoria BC and decided to head into the San Juans. Great conditions for crossing, navigating pretty much VFR with chart in hand and got fooled by the aptly-name "False Bay". When we finally got to the channel leading to Friday Harbour the tide had turned and we rode a bit of a white knuckle white water through the pass (I've forgotten the name).

A few days later, leaving Sucia Island in flat calm, plenty of time so we set the sails and drifted off... half hour or so later Sucia was well in the distance.. "Aha!" we thought..."light air sailing - no sweat"...hardly a ripple on the water even.... (slow learner...)

After a while the lights came on and we realized we were in a pretty strong current, and Skipjack Island was going to be in the way. By now we're motoring flat out on a heading about 90 degrees to our COG and still sweeping down onto this island that had a bow wave, and ugly looking rapids on the 'wrong side'.

Hearts in our mouths we swept past the island with about 100 yards to spare and carried on 'down river' to Saturna and Bedwell Harbour for check-in.

Respecting the tidal currents was the lesson of the day!

sailingdog 02-01-2011 04:59 PM

Just remember that the icon on the screen of the Chartplotter is not the boat... it is the theoretical position of the boat as seen against the interpretation of the real world by a cartographer who may or may not be using accurate data. Some charts are using data that was last updated in the early 1900s and are as accurate for the given technologies of that time could make it... and may not have any real bearing on the real world.

Sailing is not NINTENDO, the boat is not the icon.... use your Mark I eyeball as your primary navigation tool, and you'll do much better than you would just staring at the boxes.

Quote:

Originally Posted by Yorksailor (Post 692531)
Back to electronics...I am on a mooring ball 200 yds off Puerto Morelos in Mexico. I can smell the bacon cooking in the restaurant.

My chart plotter shows me 880 yds further east on the other side of the reef. When I passed that reef sailing to the buoyed channel the plotter showed me 900 yds from the reef...

#1 Eyeball showed me to be exactly 100 yds from the reef. In the dark I would not have been within a mile of it and I would have hove-to in deep water until daylight.

I am using Navionics and Raymarine plotter but it is not the plotter that is wrong... it knows where I am... but the fact that the original chart is just off by 800 yds! Which is why, like Vega, I only trust the #1 eyeball.

Phil a Neo-Luddite

Neo-Luddism - Wikipedia, the free encyclopedia



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