Kayaks and Radar^

Places, technique, kayaks, safety, the sea...
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Adam_Bolonsky
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Kayaks and Radar^

Post by Adam_Bolonsky » Fri Mar 16, 2007 3:51 pm

Several seasons back one of the larger kayaking organizations in New England organized a series of radar tests with the US Coast Guard's search and rescue station at Newburyport, Massachusetts.

It was a miserably wet day with torrential rains.

The results of the radar testing were equally miserable: the Coast Guard radar watchstanders reported that they were unable to distinguish kayakers from the chaff and clutter on their screens.

It was a sobering visit, especially for kayakers who frequent the fogbound regions of downeast Maine. Maine's remote foggy waters are constantly buzzed by dodging, circling and busy-at-work lobstermen whose radar alarms are sometimes all that prevent them from colliding with others.

Have any similar tests been run formally or informally in the UK?

Similar tests were later run on a more formal and systematic basis by the Coast Guard, local lobstermen, and researchers from the Maine Sea Grant at the College of the Atlantic in Bar Harbor, Maine.

One defense: securite calls on VHF 16 that reference your working channel.

Is there anything similar to report on your side of the Atlantic?

Kayaks and radar tests:
Part 1
http://paddlingtravelers.blogspot.com/2 ... radar.html
Part 2
http://paddlingtravelers.blogspot.com/2 ... art-2.html
Part 3
http://paddlingtravelers.blogspot.com/2 ... art-3.html

VHF ch. 16 securite calls:
http://paddlingtravelers.blogspot.com/2 ... calls.html

Sea Grant pdf link (you'll need a good hour to wade through it):
http://www.seagrant.umaine.edu/extensio ... /raref.htm

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keefmac
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Post by keefmac » Fri Mar 16, 2007 4:04 pm

Similar story for the ferry from Mallaig to Armadale on Skye. Kayaks tend to blend in with the swell which is then turned off with the "squelch" control, rendering us invisible.

The only failsafe is to keep your eyes peeled and keep out of their way! (Or I guess carrying an Aluminium dust flare?!)

K

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Adam_Bolonsky
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Post by Adam_Bolonsky » Fri Mar 16, 2007 4:08 pm

keefmac wrote:Similar story for the ferry from Mallaig to Armadale on Skye. Kayaks tend to blend in with the swell which is then turned off with the "squelch" control, rendering us invisible.

The only failsafe is to keep your eyes peeled and keep out of their way! (Or I guess carrying an Aluminium dust flare?!)

K
Hi KeefMac:

A securite call on VHF 16 is one option. ("say-cure-ee-tay" in the US).

Another option (at least in the US) is a channel 13 call, also known as bridge-to-bridge (bridge being a vessel's control center for nav, radio, radar, etc.).

Your radio usage has to be crisp on 13, however, as everyone on 13 is either a professional if not a member of the Merchant Marine.

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Post by runswick2000 » Fri Mar 16, 2007 6:41 pm

In my experience, a kayak stands no chance of painting on any radar display, no matter what the set, what the environmental conditions or what the experience of the radar watchkeeper. If you are hoping that someone will avoid colliding with you by spotting you on a radar screen then you are hoping in vain.
Perhaps the greatest flaw in democracy is the idea that, if a majority of the population believes arrant nonsense, it somehow makes the nonsense true.

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ChrisS
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Post by ChrisS » Fri Mar 16, 2007 10:54 pm

In poor visibility if you have a DSC VHF radio you could set it to automatic position reporting, broadcast your MMSI number and ask all ships in the area to check your position periodically because you are invisible on their radar.

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Jim
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Post by Jim » Mon Mar 19, 2007 9:24 am

There have been a couple of informal tests years ago with various radar reflecting materials. Same conclusion as yours, totally ineffective because we are so close to sea level.

I've never really had to deal wth shipping of significant size from a kayak, I'm fairly certain I could sprint out of the way of most larger ships, but high speed craft are more of a worry, especially those from the leisure sector the crews of which probably don't even know how to turn the VHF on never mind the radar.

I think the best bet for sea kayaks is to look out for yourself, we are small and manouevrable, we have the option to stop and let other traffic past which big shipping doesn't, we also have ability to turn and get out of the way of most things. You would hope that in fog other vessels would be proceeding at slow pace and not tearing about at 40 knots relying entirely on their radar to "see". Obviously carrying VHF and signal flares is a good idea too, red may be the wrong colour for collision prevention, but it should be seen and thats going to help.

Jim

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Adam_Bolonsky
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Post by Adam_Bolonsky » Mon Mar 19, 2007 12:30 pm

Jim wrote:There have been a couple of informal tests years ago with various radar reflecting materials. Same conclusion as yours, totally ineffective because we are so close to sea level.


Jim
Thanks, Jim. One of the Sea Grant findings was that if several kayaks are packed together in a tight pod, they can be detected.

The tests were run in the Maine area because of its popularity as a destination, its persistent and thick fogs, and the large number of outfitters who run large day trips out of such areas as Deer Isle and Stonington.

Were the tests run in the UK ever printed up anywhere?

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Jim
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Post by Jim » Mon Mar 19, 2007 1:12 pm

I think Derek Hutchinson refers to his own tests in his book, and I'm pretty sure another user here, who may reply eventually, conducted some himself. I don't think there are proper reports by either though. More a case of expedition planning (probably back in the 70's) and making the effort to find out for themselves what bits of kit would and would not be useful before they went.

I seem to recall a radar reflector on a mast worked, but a mast high enough to be of any use is not very compatible with sea kayak layout :)

Jim

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geyrfugl
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Post by geyrfugl » Mon Mar 19, 2007 5:51 pm

Hutchinson's tests were of various shapes and styles of radar
reflector, mounted on top of a short mast much like a whip aerial.
The conclusion they reached was that nothing was any better than
a screwed up ball of aluminium cooking foil. From the pictures, I
guess the "mast" they used was something like a fibreglass fishing
rod mounted vertically on the aft deck, maybe a metre or so high.
Clearly that is going to be eclipsed most of the time in any significant
swell. The mast had to be flexible to avoid being capsized by a gust
(the rod bends rather than transmitting a sudden force to the boat),
and presumably to reduce the chance that the alloy foil simply blows
off.

Of course, if your metre high radar reflector doesn't work, then your
hand-held VHF radio isn't going to be a lot better. Maybe both would
work to someone who is already looking for you and at a raised
elevation (cliff-top, lighthouse or chopper...) but communication or
radar-visibility to a small fishing boat is going to be minimal...

A higher mast would increase the time during which a reflection was
available (no use when capsized:), whereas a bigger reflector might
make for a more definite radar echo during the time it was visible.

If an intermittent reflection as boats top waves would be of any use,
it ought to be possible to line the boat with foil, or incorporate a fine
conducting mesh into the fabric of a fibreglass boat ? It's a sufficiently
interesting idea that I might be tempted to try it on the next boat I
build (don't hold your breath on this one, I'm not find a lot of time
for that scale of project at the moment...)

Andy

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Freek
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Post by Freek » Mon Mar 19, 2007 6:21 pm

radar reflective kite;

www.skystreme.com

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Post by Mark R » Mon Mar 19, 2007 6:29 pm

Jim wrote:I'm fairly certain I could sprint out of the way of most larger ships
It's all well and good when you can see them coming...

Image

Crossing the Land's End/ Channel Separation Lanes in fog would be more or less my worst nightmare. Behind that big ship were a line of others, stretching away to the horizon...
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AllanJ
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Post by AllanJ » Tue Mar 20, 2007 9:03 am

ChrisS wrote:In poor visibility if you have a DSC VHF radio you could set it to automatic position reporting, broadcast your MMSI number and ask all ships in the area to check your position periodically because you are invisible on their radar.
Chris, do handhelds respond to a position poll? Also do you know what class of DCS controller you need to poll the position of another vessel (or do you get the position info back as a result of any call to a specific MMSI).

Sounds like a good idea if you are really are caught out in the fog.

I suppose we could wait for class B AIS to become small/cheap enough.

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Post by tommfuller » Tue Mar 20, 2007 9:39 am

Coming from a background in sailing, I am confident that kayaks will be invisible to the average radar. Yachts of 30+ ft with wet sails can be hard, and sometimes impossible, to spot on radar. I have frequently asked passing commercial vessels on VHF if they could see us on their scopes, and in all but the calmest conditions the answer was usually no.

This is what has driven the uptake of active radar reflectors, which amplify and return the incoming signal.

Also, don't assume anyone is actually looking at the radar!

Cheers,

Tom.

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ChrisS
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DSC VHF

Post by ChrisS » Tue Mar 20, 2007 10:51 am

Chris, do handhelds respond to a position poll? Also do you know what class of DCS controller you need to poll the position of another vessel (or do you get the position info back as a result of any call to a specific MMSI).
The Uniden Mystic can be set to Auto Position Reporting so a station that knows your MMSI number can check your position at will. I haven't actually used this feature yet but am considering suggesting it to the coastguard next time they ask me to check in with them on reaching my destination etc.

I'm not sure whether it works the other way round - that is I don't know if I could check another station's position as nobody I paddle with has a similar set.

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Post by furby » Tue Mar 20, 2007 12:05 pm

Im not a see kayaker, but I know a bit about radar.

Rather than an active radar reflector that relys on picking up a signal to send back. how about a transponder? This would be independate of a signal, producing its own which would be picked uo on the radar of a ship

I can see cost being a barrier but if you are that worried then it wouldnt be that much, esp if you had one per group for example

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Post by Stunt man Noel » Tue Mar 20, 2007 1:03 pm

Have a look at SART radar transponders on the Ocean Safety website.

They're used by liferafts etc to help SAR find them. However i believe that once activated they stay on till the battery goes (4-5hrs off the top of my head). I'd reckon that while they might be of use in busy areas they are more likely to confuse people (thinking its an emergancy) and are cost prohibitive.

But then thats all guess work really! My view is that everything is bigger than you so stay out of their likely water and if you have to go across lanes etc broadcast a Securite call or notify the VTS.

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Post by AllanJ » Tue Mar 20, 2007 1:08 pm

furby wrote:Im not a see kayaker, but I know a bit about radar.

Rather than an active radar reflector that relys on picking up a signal to send back. how about a transponder? This would be independate of a signal, producing its own which would be picked uo on the radar of a ship

I can see cost being a barrier but if you are that worried then it wouldnt be that much, esp if you had one per group for example
An active radar 'reflector' IS a transponder - in response to receiving a signal from a ship's radar it transmits its own signal which is much stronger than the reflection from a simple passive reflector.

Active reflectors are available but not cheap (500 quid ish) not easy to mount on a kayak. They only (ifaik) operate on X band.

Although the signal from an active reflector is much greater it would still be very low to the water - an ARPA radar needs to detect a target on 50% of scans to track it so if you're disappearing behind a swell every few seconds you still won't be tracked.

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Post by Jim » Tue Mar 20, 2007 3:46 pm

MarkR wrote:
Jim wrote:I'm fairly certain I could sprint out of the way of most larger ships
It's all well and good when you can see them coming...

Crossing the Land's End/ Channel Separation Lanes in fog would be more or less my worst nightmare. Behind that big ship were a line of others, stretching away to the horizon...
It helps to know that most ships are only 32m in breadth (Panamax), so the visibility required is enough to make your judgement, turn and sprint 16m.... This would be an extremely close encounter! You need to keep sprinting away to avoid as much of the wash as possible.
In theory you should be able to hear them coming, but fog takes all sense of direction out of sounds!

Of course doing an all in rescue in the path of a supertanker would almost certainly be terminal.

I think I'll continue to not paddle in busy shipping with or without fog, I'm sure it has it's attractions, but not to me!

Jim

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Post by Ryan Clements » Tue Mar 20, 2007 5:43 pm

Jim wrote:
MarkR wrote:
Jim wrote:I'm fairly certain I could sprint out of the way of most larger ships
It's all well and good when you can see them coming...

Crossing the Land's End/ Channel Separation Lanes in fog would be more or less my worst nightmare. Behind that big ship were a line of others, stretching away to the horizon...
It helps to know that most ships are only 32m in breadth (Panamax), so the visibility required is enough to make your judgement, turn and sprint 16m.... This would be an extremely close encounter! You need to keep sprinting away to avoid as much of the wash as possible.
In theory you should be able to hear them coming, but fog takes all sense of direction out of sounds!

Of course doing an all in rescue in the path of a supertanker would almost certainly be terminal.

I think I'll continue to not paddle in busy shipping with or without fog, I'm sure it has it's attractions, but not to me!

Jim
This last summer I sailed from the west coast of Scotland down to the south of Spain and the experiences we had with both fishing fleets and cargo ships was enough to assure me that any chance of being spotted in a kayak by radar is pretty much zero.It is not only a lack of reflection but the attitude of many people supervising the radar which led me to this conclusion.

Albeit we were sailing in places you are unlikely to be in a sea kayak it was quite terrifying. In the North Channel in poor visibility (200 yrds or so) we had about a dozen boats within a mile radius of us and many of them were indistinguishable from the swell even though they were relatively large (compared to a kayak) fishing vessels. Using the gain on the radar to get a clearer picture often caused them to disappear totally.... it occurred to me that radar is only really useful if you are at least bigger than the size of the swell.

As for moving out of the way of the larger ships, I wouldn't take my chances in anything other than perfect vis, the rate that they travel at and their lack of maneuverability is quite something 35+ knts and able to change course by about 10-20 degrees over more than a mile.

We berthed in La Caruna on the basque coast after we crossed Biscay and met a guy from Norway who had been ploughed in to by a french fishing boat in Biscay. His boat was a beautiful 60 ft classic which he had spent the last five years restoring which fortunately for him had a steel hull, the fishing boat road up the side of his boat snapping the steel shrouds and broke the mast in three, they were lucky to be alive by all accounts.

He was under sail at the time and had put in numerous channel 16 calls but to no avail, he changed tack to avoid them and at the last minute the fishing boat turned and went straight for them. The boat was on auto pilot and on "fish" mode which means that it pulls the nets with a periodic zig-zag motion, the crew were drunk and asleep.

We had a few close encounters with bigger tankers (a few hundred yards) despite being under sail in pretty rough conditions in a not unnoticeable boat (a 65ft teak ketch), they will not move for you at all, sometimes they can't!

The boat I was in weighed 42 tons and the only rule that really applied to being anywhere near a shipping lane or similar was "might has right".

I have not had many encounters with bigger boats in a sea kayak and radar or not I really don't want to. Just my thoughts... sorry for the long post.

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Post by Skua » Tue Mar 20, 2007 7:30 pm

I am a former merchant marine officer (2nd mate ticket).
Modern ships post a lookout, but by no means an you expect them to have an officer on the bridge during the full period of every watch. An AB (Able Seaman) is usually posted as a lookout - but they have NO radar experience whatever, are not trained to use a VHF or short wave radio - they keep a lookout - for large shipping. They then call out the OOTW (Officer of the watch) if there is a situation beyond their experience or authority - such as changing course. An AB will not take on the responsibility of changing course.

As far as the rule of the road goes with regard to ships and kayaks - the ship could be construed as "restricted in her ability to manoever" , even in open water - as to change course at short notice requires more thn 15 degrees of helm. The actual manoever of a 30,000 tonner would still require a mile or so at our normal operating speed of 18 knots - modern ships are running at closer to 23 knots.

A fully laden tanker of 250,000 tonnes going at operating speed of 18 knots requires 25 miles to come to a dead STOP even if the engine(s) is put full astern.

Your sefest option is to keep out the way!

Fishermen drunk and asleep - Rule of the Road - nothing in these rules exhonerates any owner, skipper or watchkeeper from the responsibility to keep a proper lookout.....inexcusable and would result in the immediate suspension of the skippers ticket.

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