Radar reflectors..?

[Andy Dingle]

As I'm now sailing in a busy shipping area my thoughts have been focused on seeing and being seen. I have DSC VHF and AIS (not transponder).
I don't have a radar reflector, just relying on visuals and common sense, but I now feel I should get one.
Thoughts on their use and effectiveness (especially from anyone with commercial shipping experience - Peter?) would be very much appreciated, and  if anyone uses one and can comment on their effectiveness?
My research shows that the good old fashioned 'rain-catcher' is still the best bet - unless I go for the 'sea-me' radar transponder, but that comes in at about £500.
Been pondering where to mount one too, somewhere were it won't chafe with the sails..? Off the spreaders?

Andy
Baycruiser 23 No.25 'Equinox'

Ps This is a fun/useful website which shows the position and quantity of the 'enemy'! www.shipais.co.uk

[David Hudson]

Andy

Not for Rutland?

I agree with your choice of an octahedral reflector, (square form made up of diagonal plains). The tube types advertised are worse than useless.

The best accident prevention regime will always be good watch keeping! Big ships already have too much happening on their radar etc.

I think my best safety device is my DSC VHF. I'll keep pressing the MAYDAY button as the band plays "Abide with me".

[Rob Johnstone]

Andy,
I'm afraid I haven't bothered with one. My research suggested that none of the  were reliable and linked my AIS equipped DSC  Radio to the Garmin GPS/chart plotter. This lot plot the position of the AIS transmitting boat on the chart display, green if  it's not on a collision course and in red if it is. You can set the proximity parameters for the " collision" as you think fit. The wretched thing even buzzes loudly when it thinks there's a risk. The result is that one is busy trying to remember how to turn off the alarm whilst the catamaran wind farm support vessel zooms past at  20kn. rob

[Andy Dingle]

I think I will buy the fold up octahedral reflector - they are the cheapest and, it seems, the most effective. But probably just mount it when in low visibility. I'll put a spare block on the spreaders to hoist a radar reflector, burgee's, courtesy flags etc. That seems the best bet I think.

Rob. Yes, I have the VHF/DSC polling/AIS set up on my chart plotter too, also a PC based chartplotter, the excellent Open CPN running on a Panasonic Toughbook with Visit My Harbour charts and 'live' tidal streams, with Bluetooth GPS and AIS - I want to sort out wind into it too, when I puzzle out NMEA multiplexing. (For info, I still have paper charts on a yeoman plotter).

Dave. No mate, not Rutland! Our club shares a berth with two RoRo ferries and numerous other commercial vessels. I've attached a screenshot of a chart of the dock.. To give an idea, Alexandra Dock is about half a mile long, my berth is at the western end of the narrow connecting bit.
Incidentally, the largest wind farm in the world has just been given the go-ahead to be built on the Dogger Bank, with the consequent massive development started already in the area, which has already given us new dock gates allowing 24/7 access. Combined with the existing traffic, it's going to be busy I think.
I agree with Rob, those support cats are blistering fast, gone before you even realise they are coming up behind you. Best avoided.

Still, if all does go fat tum upwards, I got a McMurdo Fast Find PLB (Don't we all if single handing?).. I'll report back if I ever have to use it, or maybe not..!

Andy

[Peter Taylor]

Hi Andy,

Since I pass through part of the Southampton dock area and sail up Southampton Water on each trip, Seatern is equipped with a class B AIS transponder and an Echomax X band radar transponder. My latest remarks about them can be accessed on my blog via:

http://www.seatern.org.uk/SeaternDiaries/firstyear02.php

I also carry a flat-pack octahedral radar reflector of the rain-catcher variety which, if caught in fog, I could hoist into the fore-triangle area using the spinnaker halyard.  My Standard Horizon radio has a "fog-horn" mode and I have a water proof PA speaker to connect to it which I can mount ahead of the companionway.  However I've never understood what purpose fog horns serve!

Anyone contemplating buying a radar reflector should read the Qinetic report... Luke 2007, "Performance investigation of marine radar reflectors on the market", QINETIQ/D&TS/SEA/CR0704527/2.0, 34pp... which is available on the web.  Having spent many hours when on research ships keeping track of oceanographic buoys using radar I can vouch for just how ineffective radar reflectors are!  I therefore chose to spend money on the Echomax transponder (which did best in a PBO test) although I didn't splash out on a dual S/X band unit.  At sea ships use S band but near port they are more likely to use the higher definition X band, which small boats also use.  If I were planning offshore passages I'd choose the dual frequency system.

Both the AIS and the radar transponder should activate a collision alarm on a ship.  However in a place like Southampton Water false collision alarms happen so often that chances are alarms are turned down or off or ignored.  If caught in fog I would hug the shallow water and watch out on my chart plotter for the AIS signal from the very fast "Red Jet" catamaran ferries which also sometimes come outside the shipping channel. The whole area is controlled by Southampton VTS (VHF channel 12) and in an awkward situation (e.g. becalmed and my outboard in a sulk) I'd make sure they knew where I was and could see my AIS/radar signal on their screens.

Peter

[Andy Dingle]

Peter.

Thanks for a very informative reply.

I must say it has swayed my thoughts somewhat on getting a radar transponder in addition to a 'passive' reflector. Certainly your comment on suffering an engine failure, with no wind, in a busy shipping area certainly focus's the mind as do these high speed very low draught boats (support and fishing vessels in my case) that do not keep to shipping lanes and tend to take the 'short cuts' - through areas where we small fry do our sailing.

What sort of power consumption does this use? Do you keep it on all the time or do you just use it at times of poor visibility/night? Do these reflect just an enhanced signal back or do they transmit your boats identity too, similar to AIS?
Mounting one may cause me a headache. The more I think of this 'boom gallow' set up, the more it appeals...

I too have the Standard Horizon GX2200e with a 'fog horn' - I believe it is a requirement to carry one, but of the 'compressed air' variety. Maybe it can be adapted to be a loud hailer to use to convey polite sentiment towards the offending skipper as he (hopefully) misses your boat by an inch and leaves you pounding around in his wake.

As you very rightly infer, common sense and good seamanship must prevail above all else.

Andy
Baycruiser23 No.25 'Equinox'

[Peter Taylor]

Andy:  The Echomax simply amplifies a received radar pulse before transmitting it back, there is no identification information added.  Also it is not legally allowed to amplify the return to the extent  that you look like a battleship, cruise ship, or something similarly large on the radar screen! In fact, at short distances <0.5nm your boats radar echo may well dominate the return.  That makes testing whether it's working somewhat difficult - mine blinks a led on the control unit to show that it is being irradiated by a radar but I don't know if it's doing anything more than that!  One day I need to find someone with a radar willing to spend the time needed for me to test it. 

The echomax power consumption is small - their tech specs state <15mA in standby mode and (typically) 32mA when being interrogated by 10 radar systems.  I leave it switched on all the time and hope that it is doing something more than just blink an led in the cabin!

You are correct that finding somewhere to put the antenna is a headache. Because x-band wavelength is around 3 cm it is easily blocked by objects such as a nearby mast.  I tried to get mine more than 10 x 3cm from the mizzen mast and simply hope that will be enough!

I thought the requirement for a fog horn was for "a means of making the required sound" - I didn't think it had to be compressed air.  I think you will find that your radio already has the "loud hailer" function if you attach a suitable PA speaker.  Certainly mine has. I also have a "RAM3" external microphone/ remote unit in the cockpit so I have the ability not only to hail the "offending skipper" but also to make the appropriate (navigational) hand gestures!

I do know my AIS transponder works. Once when off the Isle of Wight I went on to an AIS web site which is based there and was able to see where I was, how big Seatern is, and how fast and in what direction I was travelling. It was rather a strange feeling!  The AIS has to have it's own GPS (again a legal requirement) so both it and the chart plotter can feed position information to the VHF via the NMEA multiplexer.  I can also pick up the GPS and AIS data from the ais transponder (via  USB)  to display using Navlink software running on my laptop. Navlink uses the latest Hydrographic Office charts so that provides an independent back up to the Garmin chart plotter and could be really useful if I could actually see the laptop screen in sunlight!

Peter

[Peter Taylor]

However, if I was regularly sailing in shipping lanes ( like Andy ?) I would move Heaven, Earth and my children's inheritance to get an active Radar "pinger" full AIS and a dirty great searchlight!

That reminds me of my version of the "dirty great searchlight"!

I have an "Olight S65 Baton"  flashlight. On the brightest of the three power settings they claim "more then 250m throw" - using it I can (dimly) illuminate trees on the far side of the river from me... 275m away.  It's certainly very powerful and on full power it will eat batteries - a fresh set of 6 duracell AA cells will apparently only last about 90 minutes if the torch is left on using full power. It has a strobe mode which would give a bright location beacon if you needed something to last longer. It blinks an LED if the batteries are starting to get low.  On Seatern it sits in a holder just inside the companionway so I can grab it from the cockpit.

Despite being very bright it is compact - 18cm long, 3.5cm diameter, 365g weight (inc. batteries). It is waterproof to IPx8 (continuous immersion) and very well made to a military spec.  They are expensive (around £70 on the web), but cheap if it prevents a collision. It's a few years old now and LED technology has progressed so there are probably similar to be had at a cheaper price. Certainly I've seen cheaper look-alikes, but I don't know if they have the same super-brightness.
Peter

[Andy Dingle]

Peter and all.

I've sourced the Echomax transponder at £360, which is better than I originally thought it would be. Just need to work out how is the best way to fit it . Would I be right in thinking that like traditional radar reflectors, it would be advantageous to get it up as high as possible? Or is that not now as important as it reflects back an amplified signal to the originating transmitting radar?

I reckon it is money well spent, not just for being seen by the monsters I share a berth with - see the attached pic - but as Peter wisely says it will be very important for VTS to be able to pinpoint me should I get myself in a situation I would rather not be in...


Andy.

[David Hudson]

Reference to the MCA's guidance document, MGN 315 (M)
KEEPING A SAFE NAVIGATIONAL WATCH ON MERCHANT VESSELS says it all for me.

The areas that this notice covers are:
General application for Masters and officers in charge of a navigational watch; Fitness for duty;
Performing the navigational watch;
Watch arrangements, handing over the watch and taking over the watch; Maintaining a safe look-out and relationship with the look-out;
Restricted visibility, safe speed, stopping distance and vessel at anchor; Certification.

I would rather rely on keepimg a proper watch than some foreign gent with to many warnings coming up on his screen....that is if it and he are switched on!

There are no excuses in a court of law.

[Peter Taylor]

Would I be right in thinking that like traditional radar reflectors, it would be advantageous to get it up as high as possible?

Andy, obviously the higher up you can get it the better it can be seen.  However it's probably more important that it is not hidden by some nearby structure... like a mast.  The Echomax is physically small compared to a radar reflector so could easily be hidden, and because x-band radar is only around 3 cm wavelength it doesn't sneak around objects in the way that e.g. VHF radio waves can.  The top of the mast is the obvious place but there is a lot of competition for that small region.  I have the aft boom gallows so opted for that!

I would rather rely on keeping a proper watch than some foreign gent with to many warnings coming up on his screen....that is if it and he are switched on!

David, the problem is when fog closes in and you can't see what's coming towards you and they can't see you.  If the other vessel is transmitting AIS then I can see them on the chart plotter but Seatern is not fast enough for me to rely totally on taking avoiding action if something is coming. My strategy is keeping a good watch myself, keeping in safer areas (e.g. not in the shipping channel) and making Seatern as obvious as possible using AIS transmissions and an active radar transponder.  If I was in fog and had to cross the shipping channel, I'd call up Southampton VTS and see if they could see me on their radar/AIS display and check that it was clear to cross.

...for being seen by the monsters I share a berth with - see the attached pic....

See my attached pic - and yes it was taken from Seatern!

Peter

[David Hudson]

I hear what you say Peter but given the reaction time of large containerships I would rather be the  "outside half" to the "second row forward"!

[Peter Taylor]

I hear what you say Peter but given the reaction time of large containerships I would rather be the  "outside half" to the "second row forward"!

Actually the container ship is like a rolling maul about 2m from the try line - impossible to stop!
Nor, in the confines of Southampton Water and its approach, can they alter course.  They not only have right of way but also are surrounded by a "prohibited area" which moves with them.
 
I see the Echomax and the AIS transponder as a method to make Seatern more visible to all the smaller vessels that, like me, are staying clear of the main shipping channel.  This can include small ships if a "clear channel" vessel such as a container ship is on the move.

If I were in trouble in or close to the shipping channel (e.g. becalmed and outboard not starting) calling up VTS would either

(1) confirm there was time for "SeaStart" - the local breakdown service based in the Hamble - to tow me clear and/or fix the outboard - or for someone else to give me a tow.

or (2) alert them to the need for the "SP" (Southampton Patrol) launch which runs ahead of large vessels to give me a tow out of the way.  SP photo attached.

In either case having an AIS transponder should at least make it quicker to identify Seatern amongst other sailing yachts in the area. 

Of course my main strategy is to avoid bad visibility and to take care in choosing when to cross the shipping lane! I have no intention of any of the above happening -  however it doesn't harm to think "what if".

Peter

p.s. I guess SP is like a no.7 wing forward; fast and does clear-outs!

[David Hudson]

Here are two related observations on this subject from my old 5o5 helm...

http://www.morganscloud.com/2011/05/03/radar-reflectors-versus-ais-transponders/

and

http://www.morganscloud.com/2009/05/01/automatic-identification-system/

David