Single handing sleep & alarms

[matt1]

Hi Everyone - previously posted about wanting to do the AZAB in 2023

Turning my attention to sleep and alarms/ collision avoidance. The boat has full B&G (but no radar). I transmit AIS and have an echomax dual band RTE. To complete the picture I'm thinking of adding radar (probably B&G's new Halo)

Never used radar so want to get that soon to build up familiarity over the next couple of seasons. I'm assuming singlehanders set up a guard zone and have some external alarm connected to the radar / plotter. I haven't seen B&G selling a specifc alarm device so I assume you wire in anything loud enough, perhaps with a switch in the ciruit? I guess I could do the same with the Echomax for when it gets "painted"? But maybe thats duplication and too many alarms?

In reality what would you set the guard zone radius to?

Thx

 

[srm]

Prior to AIS I used to use Raymarine radar with guard zones when single handing. Any return within the zone would set off an audio alarm that continued until reset. Outer range varied depending on sea conditions and where I was, but offshore would generally set the zones from 1 mile out to five miles. You will get alarms from sea clutter as well as hard targets, hence the alarm free zone around the boat.

Now I use AIS and Echomax dual band with alarm on if no traffic in radar range - otherwise the Echomax keeps beeping with every pulse. You are unlikely to be able to use your own radar and Echomax at the same time as stray or reflected pulses from own radar will trigger the Echomax.

On Passage from south of Ireland to the Azore, summer 2014, the Echomax alarm was on and remained silent once clear of coastal traffic at both ends. We also had class B AIS turned on. I did not use the radar on that passage.

If you fit radar it is essential that you learn how to use it for collision avoidance. A radar display is not intuitive, although modern 'mini ARPA' or similar features can make it easier to understand.

 

[Roberto]

Offshore I use an AIS txr + Echomax XS RTE (definitely trust the second *a lot* more than the first). I usually do not bother with radar alarms except in specific cases (areas with boats without AIS or radar).
The problem with radar alarms is it beeps, warns and possibly wakes you up, then it cannot be acknowledged (except I imagine if one has MARPA or similar). That means that when a totally inoffensive target is in the guard zone, you cannot activate the alarm again until it has gone out, with a slowish ship coming from your stern that may mean having to wait for one two hours until it exits the guard zone to reactivate the alarm again. One of the ideas of sleep management while singlehanding is to constantly trying to accumulate precious periods of sleep: spending one hour watching an inoffensive radar target transit away from the screen is not really good

 

[matt1]

Thanks Roberto and SRM, all useful points - In particular I hadn't thought about the Echomax not being on the same time as the Radar - That's useful to know

Entirely agree about needing to know how to use the radar. I've always resisted fitting one because I doubt, being a weekend sailor, I'd ever really get sufficiently skilled to interpret it and could therefore be a liability. Sounds like you have an external alarm connected to the echomax. They look simple to connect

 

[srm]

Sounds like you have an external alarm connected to the echomax. They look simple to connect

Mine has a little black box mounted by the chart table with two switches: On/Off and Alarm. It's loud enough to wake me in the main cabin when it picks up a radar.
The RYA run a simple radar course which should give the basic elements of recognising dangerous targets and obtaining CPA, but for comparison the professional ENRAST operation level 5 week course involves the equivalent of about 15 days full time just on radar (or at least did when I last ran one about ten years ago).

 

[Birdseye]

Hi Everyone - previously posted about wanting to do the AZAB in 2023

Turning my attention to sleep and alarms/ collision avoidance. The boat has full B&G (but no radar). I transmit AIS and have an echomax dual band RTE. To complete the picture I'm thinking of adding radar (probably B&G's new Halo)

I have several times come across shipping with the AIS turned off, the last case being just this week with a tanker. They are allowed to do that in the case of cargoes that are vulnerable and of course military vessels can do so and many fishing boats dont operate AIS. So you can get an alarm from your RTE and not know where the source of the alarm really is. It could make you reliant on the other vessel to avoid you.

I prefer it the other way round. A decent radar allows you to control the situation, will give you CPA. An AIS receiver helps further with an icon on your radard screen matching the radar blip.

IMO safety means you in active control and not relying on others to spot you on their radar screen or turn their IAS on..

 

[srm]

IMO safety means you in active control and not relying on others to spot you on their radar screen or turn their IAS on..

Agreed.
The MCA probably also agree as AIS is classified as an aid with a warning to the effect of:
If your own observations differ from the AIS information act on your own observations.
(i.e. a vessel the AIS display said was at anchor but had a ground speed of around ten knots ).

 

[Zing]

Unfortunately there is only risk reduction that can be done. I have a good modern radar and know how to use it. In a decent seaway it won’t pick up a small to medium sized yacht unless it is really too close and of course many don’t even have AIS transmitting. For radar to be of use in the way you hope I think you need a 6’ open array. Not too practical usually. Big ships are easy to pick up OK though.

 

[srm]

In a decent seaway it won’t pick up a small to medium sized yacht unless it is really too close and of course many don’t even have AIS transmitting.

My older Raymarine set often had trouble picking up such yachts at one or two miles in fairly calm conditions.

Unfortunately, there are pieces of kit sold under the name of 'radar reflector' that in real life conditions are no more use than a St Christopher medallion. If your radar reflector can not give a consistent return back to a ship at five miles range in real sea conditions its not worth the cost and effort of fitting it. You won't be seen when it matters.

Modern ship radars have noise filtering circuits, so an intermittent signal is likely to be filtered out along with the sea clutter. An effective radar reflector is a physically big item and even then only works for the 3 cm band.

 

[michael_w]

My setup when running not under command in deep ocean was to switch the alarm on the Sea-Me. On hearing a regular alarm I'd turn the radar with a guard zone on. My radar has an effective range of 10 miles.