AIS - Value in Open Ocean

[TonyMills]

Hi,

I'm planning a personal Jester style single handed challenge starting in late August this year, intending to cross the Indian Ocean from Perth stopping at Cocos Islands, Rodriguez (Mauritious) and returning Via St Paul & Amsterdam Islands (all things being equal with the French and the weather).

I am installing a AIS engine as part of my watch keeping aids, particularly when getting a little sleep! (Providing I can make the alarm function work through SOB on the laptop)

I understand that AIS is required on all ships over 300 tons, but can the forum advise on whether or not AIS remains transmitting (not switched off) when the ships are in the open ocean (ie not approaching port or in busy traffic schemes).

My objective is to improve percentages.

Regards
Tony

 

[Noddy]

I used AIS on JAC08. (Atlantic)

I can report that the unit woke me up when a ship with its AIS turned on passed by. I am unable to report on instances where the ship had AIS turned off or I slept through the alarm. /forums/images/graemlins/grin.gif

But seriously - I don't remember seeing any ships and thinking that the AIS was not on. So I guess that they mostly keep it on (legal requirement??).

If money and electricity generation were no object I would probably opt for radar with a proximity alarm (as well??).

Hope that helps

Your trip sounds great - What is the likely problem with the French? They keep winning the bloody Jesters round here but other than that they seem OK.

Paul

 

[alexrunic]

a few years ago i was on a mates boat with AIS and did come across a couple of ships that did not have it switched on in the north sea. i believe some of them don't like if as they are scared of piracy an industrial espionage

 

[Wunja]

Is there a lot of piracy on the North Sea (East Coast forum excepted)? I'm planning to cross in April and would like to know if I need to be prepared to repel boarders. /forums/images/graemlins/wink.gif

 

[Gargleblaster]

I did a crossing in 2005 from the West coast of Florida down to Cuba, across to the Bahamas, then to Bermuda, the Azores and England. We ran a constant watch system but also had the AIS on at all times [We had plenty of batteries and a stand alone diesel generator - after all we had to run the microwave]. We were amazed at the number of ships that weren't using the AIS or at least we weren't picking up. Particularly in the very busy shipping lanes where the Gulf Stream runs up between Florida and the Bahamas. We were lucky to have 50% of the ships that we observed and logged with their AIS on. And I understand that it is mandatory under US law for all ships over xxxx tons to have their AIS switched on. Maybe like the North Sea ships they thought that Edward Teach [Blackbeard] would suddenly appear and try and take them over.

I would not rely on AIS for that reason. But I also try and cut my power use down to minimal level and would not be running a laptop constantly nor a stand alone AIS receiver. I even turn my VHF off most of the time and only turn it on if I see a ship or a sail.

 

[stevenhumphrey]

am putting one on, as just 1% of being seen and not run over is still good?

 

[lumphammer]

My AIS died on the way out to the Azores and as far as I could tell most days there were no ships around.

Using a replacement on the way back I was surprised that there were generally 2 or 3 ships a day within VHF range, most of which I never saw, so the apparently empty ocean wasn't as empty as I thought !!

In my view if power/money/weight was no object I would go with radar, however in the absence of radar any information about what is out there is better than none.

 

[CPD]

AIS was without a doubt the most useful bit of safety kit I had on board during the JAC08. I didn't see a vessel that should have transmitted tat wasn't, and it woke me on 4 ocassions warning of ships within the alarm zone (NASA AIS Radar). As John says however, dont fully rely on it. A forumite on the East coast is a pilot operating from Felixstowe, and told me once that a surprising number of large vessels arrive 9 and depart from port apparently forgetting to activate their AIS boxes.

 

[TonyMills]

Thanks for that advice.

St Paul Island is a volcano caldera with a small entrance and a large protected lagoon (from the prevailing westerly's and most other points). It has been unhabited since the early part of the last centuary and is treated as a reserved area with no one allowed to go there unless with special permission and an accepted environmental research project. I have sought permission and was told to go to Amsterdam 80 miles north, but this has no protection or shallow water anchorage - no real use at all. The other suggestion was to go to Kergelan which at 52 degrees great anchorage but means I would need to cross the roaring forties into the furious fifties. I think they were serious!!

I know of a couple of yachts who have stopped at St Paul and anchored in 20 metres (Mithril of Ireland being one). In the right weather conditions it would enable me to break the long haul back to West Oz.

Kind Regards
TonyM

 

[TonyMills]

Thanks for all the good advice. I am fitting it but given your experiences will use it as a percentage safety device.

The ships I am likely to come across between Cocos and Mauritious will be travelling to and from known piracy areas and it concerns me that they may take decision to turn off for that reason - well see. I'll report back when I get back.

Kind Regards
TonyM

 

[Gargleblaster]

G'Day Bunyip

One other thing you should be thinking about is good radar reflectors, if you are worried about shipping. A number of times I have had ships tell me that they have seen me on radar from below the horizon and came to have a look at what is a relatively small blip for them. One Dutch ship that came up behind me one evening said they had had me on their radar for an hour. Now I was doing about 5 knots at the time and they were doing 20 knots, so at that rate they had me on their radar for 15 miles.
On my mast I have a Sestrel radar reflector, one of those things with aluminium sheets enclosed in a fibreglass tube. On my backstay I carry the larger 'raincatcher' radar reflector in the correct position to reflect the maximum. I know a lot of people also swear by the SEEME active radar reflectors, but I am concerned about anything requiring power and have never been able to get anything to stay at the top of my mast for a whole ocean crossing. The SEEME also only reflect 'X' band radar waves and for long distance work, such as at sea, ships tend to use the 'S' band. I may have that around the wrong way.

Bill O'Bong