Thinking About AIS, Radar, Night Sailing, Tankers Etc.

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Rick D

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Jun 14, 2008
7,204
Hunter Legend 40.5 Shoreline Marina Long Beach CA
So, I got back yesterday from Ensenada, Mexico where we picked up a second in this 65th race from Newport Beach. The loss of Aegean prompts this missive:

I had two new crew this year so I made myself the fifth 'floating' crew. It was a good idea. The new crew had an awful time at night sorting out what they were seeing. I've become used to it, but it's scary when you haven't experienced it a few times. We did three hours on and three off. I have tried four, but always come back to three.

Radar was a mystery to most. They could not figure out what range to set it and consistently were out way too far. At least it caused them to ask me what a target was.

I purchased Polar View but had a problem with it dropping the AIS feed. I have an inquiry to them. No problem with Open CPN or SeaClear. In general, the PC navigation was, in my estimation, much more useful than my older Raymarine chartplotter, but I trusted the Raymarine more.

My new night vision scope from Bushnell (
Bushnell StealthView - Monocular 5 x 42) was a serious improvement over the older unit I had before. It was useful in finding the marina entrance and watching out for unlit buoys.

We had an issue with a tanker on the way back. We were motoring up the Mexican coast at night. The watch crew tracked a vessel from 12 miles to 4 and called me up. I put in an EBL on the radar and watched for a half hour as it marched right down to us. I put out a call on 16, but no response. I shut down Polar View which had no AIS info and pulled up Open CPN and the AIS info appeared. It was a tanker also headed north, but 30 degrees east, so we were closing. I went back to the cockpit and called him by name. He answered right away and said he did not see us when I gave him the coordinates. We shot a 500K spotlight at him; he replied he did see us now. He advised us to stay on course. I watched him fall off to 5 knots and fall behind us. We checked in twice more. The point is that to him we were invisible. I doubt a class B transmitter would have helped since he probably had them screened out. He was responsive and courteous. I was running a radar reflector.

I find a flat LED gun handle light to be invaluable at night to check sail trim. Being flat, it stays put. having a gun handle with trigger makes it easy to grasp and activate. It's a big deal. But, you still need a big candlepower spotlight too.

Anyhow, just some random thoughts to share.





 

Joe

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Jun 1, 2004
8,323
Catalina 27 Mission Bay, San Diego
Good stuff Rick, thanks....oh and congratulations on the podium finish.
 

Kordie

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Aug 7, 2011
144
Beneteau 393 Cruising Baja
I installed the Raymarine E7 and their AIS650. Used it from Oxnard down to San Quintin then back to Ensenada.

Some issues with SWR faults but a new antenna connector seems to have solved it.

Certainly very useful for tracking vessels from a long way off. I know it is VHF but I guess the ships antennas are high enough that we seem to see them over the horizon.

I think a decent spotlight is now on my shopping list. Not being familiar with US brand names I'd appreciate any advice :)
 

Tom J

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Sep 30, 2008
2,325
Catalina 310 Quincy, MA
Outstanding that the tanker responded and actually changed course for you. Very professional crews on the tanker and your boat.
 

Tim R.

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May 27, 2004
3,626
Caliber 40 Long Range Cruiser Portland, Maine
... I doubt a class B transmitter would have helped since he probably had them screened out...
Nice write-up Rick, but I would disagree with this. No way to know that unless you asked. I have a class B transponder and have been contacted by name a number of times by commercial vessels in busy shipping lanes.

Look at it as just another possible way for someone to see you. They have come way down in price and are very easy to install yourself. If you are doing a lot of night or off-shore work, you have no good excuse for not having one.
 
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Nodak7

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Sep 28, 2008
1,256
Hunter 41DS Punta Gorda, FL
I installed the Raymarine E7 and their AIS650. Used it from Oxnard down to San Quintin then back to Ensenada.

Some issues with SWR faults but a new antenna connector seems to have solved it.

Certainly very useful for tracking vessels from a long way off. I know it is VHF but I guess the ships antennas are high enough that we seem to see them over the horizon.

I think a decent spotlight is now on my shopping list. Not being familiar with US brand names I'd appreciate any advice :)
Kordie, I upgraded mine this year and purchased a Streamlight Waypoint. Been very happy with it. Lightweight, waterproof, pistol grip and will operate for 8 hrs without a charge (on Low).
 
Oct 2, 2008
3,811
Pearson/ 530 Strafford, NH
Hi Rick D,
I had those same questions last weekend for the service manager at our yard and he sent a tech over to our boat to see if we were transmitting an AIS signal. I had the Marine Traffic on the laptop and thought I would see our boat since there was another large yacht on the screen nearby. Yes, we were transmitting along with about a dozen other boats. No we weren't on the screen because the tower's signal was being blocked as well as the other boats. He did mention Class B signals being dropped in high traffic areas, (NYC).
This makes me a bit uneasy while cruising through the traffic lanes. Makes me wonder about traveling through the fog even with the horn sounding.
Nice job with the race.
All U Get
 

zeehag

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Mar 26, 2009
3,198
1976 formosa 41 yankee clipper santa barbara. ca.(not there)
i covet your night vision capabiity.
i dont use ais and i love night sailing--dark moon is ok but full is best---is peaceful out here at night--freighters are visible for miles. islands are less visible, but at least are on charts, both gps and paper, so , so far, so good....
and remember, gps and spot are a lil inaccurate, so plan accordingly--i give a couple hundred yards leeway in planning courses, and nothing is automated, i have to enter everything into my gps and auto pilot for course adjustments.

good work in the race----sad about the aegean. we all need to be aware always.
 

Rick D

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Jun 14, 2008
7,204
Hunter Legend 40.5 Shoreline Marina Long Beach CA
AIS Class B & Spotlights

Here is the spotlight which is always on deck at night and used for sail trim:
http://www.buy.com/pr/product.aspx?sku=230437767&sellerid=16881584
Here is the big one used for longer distance:
http://www.defender.com/product.jsp?path=-1|65136|8049|320401&id=66118
It was the big one we signaled the tanker with.
I am of two minds regarding class B AIS transponders. While I agree with Tim that you might be better off with one if the shipping hasn't tuned you out, I abhor the clutter of so many and if you are a commercial ship in my home port area, you just simply have to tune them out. Having said that, I wished I had one when that tanker could not get a visual (or radar?) from 3 to 2 miles away. On the other hand, his identity was ascertained by my receive-only box and it worked as intended. Like I said, I am of two minds on this and can argue with myself all day.
 
May 11, 2005
3,431
Seidelman S37 Slidell, La.
Night time

For sail trim at night, I have two little solar powered spotlights, mounted up high on the bimini frame, aimed at the sails. They are not real bright, and do not interfere with night vision, but do enable you to see the sails fairly well.
 
Dec 2, 2003
1,637
Hunter 376 Warsash, England --
Radar Not Seeing Yachts - A warning to All.

In 2006 we had a yacht simply disappear when sailing at night. It departed on a 50 mile journey but never arrived. No wreckage has ever been found. Three bodies were subsequently recovered all with inflated lifejackets. All died of hypothermia only one was wearing crotch a strap so the others' PFDs were up above their heads and providing little 'freeboard'. The one with acrotch strap survived several hours longer than his two colleagues.

It was understood that a radar reflector was carried on the yacht's mast.
It was a clear night with a force 4 wind (15 Knots).
The sea was quite choppy.
It seemed likely that a cross channel ferry might have been in collision with the yacht.

Our (UK) Marine Accident Investigation Branch carried out an extensive analysis and examined the voyage data recorder of the ship (like the 'Black Box' on an aircraft). No sign of any returns from the yacht had been recorded. They then commissioned a UK government research laboratory (Qinetic) to study responses from radar reflectors and they generated the simulated theoretical graph below. Google MAIB Ouzo incident and Qinetic for full reports.
The chart shows that, regardless of the size of their radar reflector, there are several distances where the ship's radar will just not be able to 'see' a yacht. These distances are where the probability of detection drops to zero on the graph.
The loss of return echo occurs because of the direct echo being cancelled out by that reflected from the surface of the sea. The nulls will be at different distances depending on the height of the ship's scanner and the yacht's reflector. But they will exist in every case.
In this instance they occurred at 1, 1½, 2 and 4 nautical miles.
If the navigating officer only looked at his radar at intervals which happened to coincide with the nulls the yacht would not have been noticed.

This may be the reason you were not seen.

Moral:- Never rely on a ship seeing you. Most rely absolutely on their radar in preference to looking through the windows and they now have a ready made excuse for running you down.

Having AIS receive only puts full responsibility on me and that is how I prefer it to be.
I also carry a zillion candlepower sealed beam car spotlight running off the house battery. The feeling of satisfaction was wonderful when I gave it to a Royal Navy destroyer straight between the eyes one night when entering Portland Harbour (where the Olympics Sailing will be).
Then I lived in fear that the military police would be waiting on the dock for me when we got in - but the Navy made no complaint.
 

Attachments

Feb 26, 2004
23,353
Catalina 34 224 Maple Bay, BC, Canada
Don, yes, I read that full report. The boat's name was Ouzo or something like that. I came across it via the www.ybw.com website / forum. Interesting read based on their course, attempts at avoidance of the ferry, being in the ferry land to begin with, etc...
 
Sep 4, 2010
51
Beneteau Mooring 352 PUERTO LA CRUZ
I am planning to sail from Puerto La Cruz, Venezuela to St. Thomas US Virgen Island, crossing the caribean from south to north, heading 358. I have outpilot, radar, GPS chartpotter. Do you thing it is necesary to install a pair of radar reflector in my boat in the stay, if so any sugestion?
 

zeehag

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Mar 26, 2009
3,198
1976 formosa 41 yankee clipper santa barbara. ca.(not there)
always a good idea to have radar reflector. also a good idea to use lighting on sails--is a life saver. been doing that since i was 16 on hudson river when i awoke from my on watch doze i shouldnt have been doing to see a freighter up close and personal and had to light em up for safety and avoidance.
 
Sep 25, 2008
544
Bristol 43.3 Perth Amboy
sirocovzla said:
I am planning to sail from Puerto La Cruz, Venezuela to St. Thomas US Virgen Island, crossing the caribean from south to north, heading 358. I have outpilot, radar, GPS chartpotter. Do you thing it is necesary to install a pair of radar reflector in my boat in the stay, if so any sugestion?
I think the mobri type reflectors have tested far inferior to the Davis type. On my old boat I assembled one on my backstay. Boats could see me very well on their radar when I asked the. My new boat has a permanent reflector (flipper) on the mast. I am visible at over 10 miles to commercial traffic in 5 foot seas. I also have a Davis that I hoist in the fog as well.

You should most definitely have a reflector. Don't even think about it.
 
Jan 4, 2010
1,037
Farr 30 San Francisco
This report suggests the best reflector is the Sea-me active reflector.
Basically retransmits the incoming radar pulse gives the boat an apparant 100sq meter radar cross section.
 
Apr 22, 2001
497
Hunter 420 Norfolk, VA
AIS Class B & Spotlights

Tim,

I have to agree with Nick about AIS-B...
While it would be beneficial for pleasure craft to have an AIS-B transponder; IF used responsibly ...
do you not see the day in the near future, when so many (smaller) pleasure boats have installed AIS-B that the clutter on everyone's chartplotter becomes so egregious that everyone ... (pleasure craft, as well as commercial ships) acquire AIS receivers that can filter out all of the needless, bothersome, pleasure craft clutter.... making AIS-B essentially worthless.
Over the last year or so, I have even been seeing examples of pleasure boaters leaving their AIS-B equip on, even when they are tied up in port !
IMHO, sadly, AIS-B is becoming another example of "too much of a good thing, is becoming a bad thing ".
 
Dec 2, 2003
1,637
Hunter 376 Warsash, England --
Why I don't Trust Ships.

Stu,
The 'Ouzo' was only four or five miles off the Isle of Wight.
The local Portsmouth VTS radar showed the P & O ferry to be heading close to where the yacht was believed to be at the time but, due to the projection of the island obscuring the actual location, they did not see the coming together of the two vessels.
The 3 bodies were found in that area a day or two later and after allowing for tide and wind drift.
It was a clear night but, at the last moment the lookout saw a light only two hundred yards away which (apparently) passed down the starboard side.
They claim to have seen it again behind them. Afterwards the VDR showed nothing.
The ship's lookout was using spectacles which darken in sunlight and these only went to 80% clear at night - but nobody knows if this was relevant.
(BTW - I imported a sample pair of the first Corning Photogray lens blanks into the UK 40 years ago and had the only pair of sun dimming glasses in Europe! I tested them too and they only went to 80% clear)

But the killer blow was that the bastards did not stop - nor did they report the incident to the Portsmouth VTS or Coastguard.

Just like the other P & O ship that ran down the Moody yacht Wahkuna a year or so earlier.
That case was proven by our investigators flying out to Hong Kong and finding 'Moody' blue antifouling paint on the ship's bow.
It was thick fog, they could only see half way from bridge to bow but were steaming at 27 knots (30mph) which is faster than their normal service speed in order to make up for time lost in clearing their last port. They did see the yacht on their radar from 6 miles away. The yacht also saw the ship on theirs too.
They also did not stop or report a possible collision after seeing an echo behind them.
The Wahkuna had lost 10 feet off its bow and was full speed astern to try to stop flooding. She sank minutes later.
In this case the 3 on board drifted for 24 hours in their liferaft and right in the shipping lanes too. Their McMurdo EPIRB was activated but, despite having been serviced only a month or so previously, it did not operate because of poor contact with its battery.
24 hours later, after the fog had cleared, a passing high speed ferry just happened to notice them as it went by at 35 knots.
Joburg VTS saw 20 ships pass in that 4 hour period. The fog was dense - less than 100 yards viz. Only two were steaming below their normal speed.

Read full reports by Googling 'MAIB' and selecting Ouzo and Wahkuna.
 
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