Visit our Popular Forums

goboatingnow · 29-08-2013, 16:21

Quote:

Originally Posted by conachair

In the real world for most people yes, but technically no..

http://www.dft.gov.uk/mca/mcga-mnoti...8E08C2F38A0072

"There is no provision in the Collision Regulations for the use of AIS information therefore decisions should be taken based primarily on visual and/or radar information."

As for everyone transmitting, in the busier areas it can get very cluttered and is nowhere near as useful for knowing what the big boys are up to. Check out the solent on a busy Saturday. Little boats are much easier to dodge.

Irrespective of the COLREGS its clearly set put in the IMO preface as a collision avoidance tool.

As for busy areas. There was a big thread on that here on CF, so lets leave that one as a somewhat red herring

Dave

madsb · 29-08-2013, 16:38

Quote:

Originally Posted by conachair

Guidance & Regulations

"There is no provision in the Collision Regulations for the use of AIS information therefore decisions should be taken based primarily on visual and/or radar information."

Quote:

Originally Posted by COLREGS

Rule 5
Look-out
Every vessel shall at all times maintain a proper look-out by sight and hearing as well as by all available means appropriate in the prevailing circumstances and conditions so as to make a full appraisal of the situation and of the risk of collision.

Actually it was my interpretation that the "all available means appropriate" would include AIS if present on the ship.

**roverhi** · 29-08-2013, 16:41

The Germans invented a reciever to pick up radar signals while they were running underwater on the diesels with their snorkels supplying air. Unfortunately, the allies figured out a way to sense the Uboat receiver and hunted them down using the Uboats own protective device. Assume the radar detector gave out some kind of rf energy that the allied ships and planes could pick up.

Think you are being a bit paranoid. No I wouldn't turn the AIS on in the Western Indian Ocean or Red Sea but would in most places where cruisers go, it's really nice to know who else is out there if they have an AIS. No excuse for not keeping watch, however.

Thought there was requirement that ships above a certain tonnage or length had to transmit AIS information. It's not 100% coverage but it does give you information about most of the BIG guys. One thing I did find a bit disconcerting was a tug towing a barge that crossed my path. There was no indication on the AIS what the vessel was only the vessels heading and speed. I could see the tug and tow when it got close and was never in any danger of crossing between it and the barge. Still, would have been nice to know that there was a barge behind the tug if I'd been passing astern in poor weather and visibility.

DotDun · 29-08-2013, 17:06

Back to the privacy issue raised by the OP...

What value is there in having real-time AIS information published on the Internet?

The value seems to be the owners of the website gaining by pimping your private information. (Oh, wait, I guess that throws them into the pool with all the other social websites, FB, Myspace, etc.)

But, there is a difference between one volunteering private information on FB and MarineTraffic.com, Shipfinder.com, Vesselfinder.com, and the likes. These AIS sites are broadcasting your private information worldwide without your permission.

Yes, anyone with an AIS receiver can see my vessel AIS data within the VHF range of my transmitter and their receiver. That is how the system works and what it is designed to do. In this example, the information about my vessel is used in navigation, as a collision avoidance tool. All good! Those that see my vessel in this context aren't interested in exploiting that data for their monetary gain. Sure, piracy will adapt to new tools, but piracy isn't the norm so if I'm in an area I believe there might be such a thing happen, I'll go into 'stealth' mode.

It is very easy to write a script to visit these websites every few hours and gather data on any AIS transmitting vessel within range of these websites receivers. Using this script every few hours, one would not only know your current location, but where you've been for as long as you've been transmitting AIS and within range of a station sending data to the website. Is this 'creepy'? Yes, some cruisers create blogs/websites to share exactly such information, but not all cruisers desire to do so.

What would you think about anyone/everyone tracking every move of your car? What if there was a GPS receiver in your car coupled with a transmitter and a public website anyone could go and re-create the last 24 hours movement of your car? I would think any government in a first world country would shut down such a 'service' pretty quickly. Yes, there are lots of webcams viewing public areas, but none that publish personal identifying data, and that is the difference. Being seen as a generic figure in public is typically not considered a breach of privacy, but allowing unknown tracking of a vehicle and/or person crosses that line. Hence, maybe there needs to be some higher government awareness of these AIS tracking sites.

So what is the solution?

1) What would the value of MarineTraffic.com, Shipfinder.com, Vesselfinder.com be if they did not display the static data, but just the dynamic data? They would still have pretty screens with little ship icons moving around. Probably a lesser number of viewers that results in a lesser amount of money collected from advertisers.

2) What if display of static data was a simple 'opt-in' feature? IOW, the proven vessel owner would agree to the display of static data. That would protect the privacy of those that have such desire, and also allow those who wish to be seen and identified.

Bregts · 29-08-2013, 17:07

I crossed the bay of Biscay two weeks ago from Falmouth, U.K. to A Coruna in Spain. On our way we crossed the line between the shipping lanes of Brest and Finisterre at a very small angle and our AIS transponder/receiver was a great help as it was very busy around us for about 48 hours. Big ships everywhere!
ALL ships we met on this 500 miles track where sending AIS except one small fishing boat when we where close to Spain. We could see the big guys change course better and further away then when we where sailing without the AIS transponder last season.
Listing all the advantages would take to long but the most important ones for me are that other ships know right away I'm a sailboat and the CPA even out of sight and that I'm able to call ships and they us with the name or MMSI on ch16.

We also used it to call a ship (by name) coming from Finisterre that was out of sight when coming closer to Spain to ask for the weather situation near the cape. (Our navtex stopped working)
Without AIS we would have never seen this ship and therefor would not have gotten this weather report.

MarkJ · 29-08-2013, 17:13

Radar is BS for what you lot are talking about and what Colregs talk about. That's Radar with APRA and only commercial ships have it.
At best we have mini-APRA which is not the same as there is no A in it... It's not automatic. So ships have automatic acquisition by sailboats don't. So you have to do the acquisition. Then it will track ONE only target at a time unlike the multiple a ships will.

AIS is automatic acquisition so any deadhead can alarmed till he looks at the machine.

For lil boats like us AIS is vastly superior to RADAR because it works when we fail!

Mark

Albro359 · 29-08-2013, 17:28

Paranoia about bad guys.....? I doubt there are that many out there except in known pirate regions - African est coast, south Chine sea etc.
Safe navigation requires as much observation as possible.
One tool cannot be relied upon.
AIS is very useful, but it doesn't see boats that don't transmit, and sometimes doesn't see them even if they are transmitting.
A radar set with ARPA on the other hand allows one to identify targets and track them, course, speed, TCA etc...but it requires the user to identify the target first generally.
Radar reflectors are generally useless. The only ones that come close to be being useful are active ones that transmit a signal. There was a big study done in the UK some years ago that demonstrated this.

BUT all these devices are navigation aids and none of them overrides keeping watch and a good lookout.

DotDun · 29-08-2013, 17:41

Quote:

Originally Posted by MarkJ

At best we have mini-APRA which is not the same as there is no A in it... It's not automatic. So ships have automatic acquisition by sailboats don't. So you have to do the acquisition. Then it will track ONE only target at a time unlike the multiple a ships will.

Don't know what radar you have, but from the Furuno manual -

Quote:

The ARPA (Automatic Radar Plotting Aid) shows the movement of a maximum of 30 radar targets. The targets can be acquired manually or automatically.

Bash · 29-08-2013, 17:43

Quote:

Originally Posted by DotDun

So what is the solution?

One fairly easy solution is to stop transmitting when you're in port.

There's a button for that.

Bash · 29-08-2013, 17:44

Quote:

Originally Posted by MarkJ

At best we have mini-APRA which is not the same as there is no A in it... It's not automatic. So ships have automatic acquisition by sailboats don't. So you have to do the acquisition. Then it will track ONE only target at a time unlike the multiple a ships will.

My Raymarine radar has MARPA that tracks multiple targets.

Tim R. · 29-08-2013, 17:48

Quote:

Originally Posted by goboatingnow

Sure sure, In my view receive only should never have been promoted or allowed. But it arrived because classB took so long to get to market. hopefully as prices fall RX only will die away.

TIMR, what do you mean boat-to-boat, AIS is much bigger then boat to boat.( AIS ATONs, virtual ATONS, Satellite AIS, VTS via AIS, shore control of AIS, etc, etc, safety messaging,etc)

dave

Sorry, i should have said the only targets an AIS receiver will pickup is what is transmitted from another boat, ATON, etc The statement was meant to convey that online AIS mapping is not accurate and cannot be relied on.

DotDun · 29-08-2013, 17:56

Quote:

Originally Posted by Bash

One fairly easy solution is to stop transmitting when you're in port.

There's a button for that.

The receivers are not only in ports. Lots of coastal coverage out 20-30nm.

The main point still remains, it's more of a privacy breach than any other Internet application.

Albro359 · 29-08-2013, 18:06

Our Furuno NavNet can acquire targets automatically and track multiple targets...depends which radar you choose...MARPA is not just for the big boys.

conachair · 29-08-2013, 18:56

Quote:

Originally Posted by madsb

Actually it was my interpretation that the "all available means appropriate" would include AIS if present on the ship.

It's how I use it anyway.

Or to be precise, to avoid a close quarters situation arising in the first place.
Personally, I put having a strong radar return a bit above transmitting ais.
Anyone worried about privacy transmitting shouldn't really be posting on the internet