VHF - hailing an unknown ship (in the middle of the night)

[prv]

He doesn't need AIS to know that you are under sail.

Presumably he does if he's making avoidance decisions at ten miles out, though? Or is that within range of decent binos from a high-up bridge?

On the back of this thread I've just been looking into AIS transmitters (currently have receive-only, and wouldn't want to be without it in the Channel), and it seems like all of the Class B ones have to be initially programmed with a PC and then the values are static. So we can't properly indicate whether we're under sail or not - I assume some people pick "Sailing Vessel" from the list and are then "lying" when under motor, and others pick some variety of motor vessel and are then not sure whether to behave as one for consistency, or whether the OOW has seen their sails and is treating them as such.

Really we need the AIS manufacturers to give us a switch - preferably a pair of terminals to which we can wire our own - with which we can instantly select between the two states.

(If Digital Yacht or someone are reading this, what I'd *really* like is a common terminal and three others, so I can wire up a rotary switch and choose between "Transmit Off", "Motor", "Sail", and "Anchored" . "Motor" to be selected as the default when none of the terminals are connected to common. )

Pete

 

[Dockhead]

Presumably he does if he's making avoidance decisions at ten miles out, though? Or is that within range of decent binos from a high-up bridge?

On the back of this thread I've just been looking into AIS transmitters (currently have receive-only, and wouldn't want to be without it in the Channel), and it seems like all of the Class B ones have to be initially programmed with a PC and then the values are static. So we can't properly indicate whether we're under sail or not - I assume some people pick "Sailing Vessel" from the list and are then "lying" when under motor, and others pick some variety of motor vessel and are then not sure whether to behave as one for consistency, or whether the OOW has seen their sails and is treating them as such.

Really we need the AIS manufacturers to give us a switch - preferably a pair of terminals to which we can wire our own - with which we can instantly select between the two states.

(If Digital Yacht or someone are reading this, what I'd *really* like is a common terminal and three others, so I can wire up a rotary switch and choose between "Transmit Off", "Motor", "Sail", and "Anchored" . "Motor" to be selected as the default when none of the terminals are connected to common. )

Pete

The data transmitted is part of the AIS specification, so it's not up to the manufacturers to vary.

Class "A" sets have come down in price, and I actually considered buying one. But the problem is that you have to program voyage data of different kinds (not just nav status), every time you go out. The work load is excessive for the short-handed recreational sailor. So I took a pass.

But I have been quite satisfied with the performance of my Class "B" set in practical usage. And I've had a lot of it, since I've been down into Biscay, and done four full transits of the North Sea and the Baltic, as far as Russia, since I installed it. I really don't think that broadcasting nav status is all that important. You can see a sail from 10 miles out with your bare eyes, from the height of a ship's bridge. And as I wrote, you don't really care all that much, if the ship decides to stand on -- AS LONG AS you are able to perceive that he is doing so, so that you can take your own action. You can easily perceive that, with AIS.

 

[prv]

The data transmitted is part of the AIS specification, so it's not up to the manufacturers to vary.

I know - I wasn't assuming that they could transmit whatever they felt like. I was specifically referring to the Navigational Status field:

• 0 = under way using engine,
• 1 = at anchor,
• 2 = not under command,
• 3 = restricted maneuverability,
• 4 = constrained by her draught,
• 5 = moored,
• 6 = aground,
• 7 = engaged in fishing,
• 8 = under way sailing,
• 9 = reserved for future amendment of navigational status for ships carrying DG, HS, or MP, or IMO hazard or pollutant category C, high speed craft (HSC),
• 10 = reserved for future amendment of navigational status for ships carrying dangerous goods (DG), harmful substances (HS) or marine pollutants (MP), or IMO hazard or pollutant category A, wing in ground (WIG);
• 11 = power-driven vessel towing astern (regional use);
• 12 = power-driven vessel pushing ahead or towing alongside (regional use);
• 13 = reserved for future use,
• 14 = AIS-SART (active), MOB-AIS, EPIRB-AIS
• 15 = undefined = default (also used by AIS-SART, MOB-AIS and EPIRB-AIS under test)

However, I've since learned that the Class B format doesn't include Navigational Status. Boo!

Seems rather silly really, especially when they have spent 7 times as many bits encoding the location of the GPS antenna on board, which is completely irrelevant for the size of vessel likely to be using Class B. Yet we're far more likely to be sailing, or fishing, or aground (admittedly that last one unlikely to matter to anyone else) than Class A users.

But I suppose there's not a lot anyone can do about it now.

Pete

 

[BrianH]

Class A navigational status has to be entered manually and from my experience in the Adriatic often wrong - typically still 'moored' while clearly underway, or 'destination' still the port from where they are departing, for example. I believe recreational sailors will be even less thorough than their professional counterparts in keeping this data updated and so it will become just as suspect.

 

[Dockhead]

Class A navigational status has to be entered manually and from my experience in the Adriatic often wrong - typically still 'moored' while clearly underway, or 'destination' still the port from where they are departing, for example. I believe recreational sailors will be even less thorough than their professional counterparts in keeping this data updated and so it will become just as suspect.

Absolutely. It would be a disaster, I think, if recreational sailors were expected to do that.

It would be nice if it were optional -- if you could enter nav status and destination and so forth if you're on passage, but just broadcast the "B" data when you're pottering around the coast. This could be done easily -- with two AIS sets on board -- one "A" and one "B". Would be the ideal solution if you didn't mind the complexity, but I'm afraid I WOULD mind such complexity, personally. My electronics are complex enough already.

 

[alant]

I know I'm jumping into this thread a bit late, but given the importance of such calcs here's my tuppence worth. I too find Dockhead's comment somewhat extreme; moreover it's a defeatist attitude completely out of sync with the teachings of the RYA:

"Considering all of this, it should be no surprise that many recreational sailors are not really able to avoid a collision with a ship in open water. We rely on the ships to create the solution and do the maneuvers. Which they have generally done long before we are even aware that they are there.

"What professional mariners say about this is that they calculate their maneuvers so that the crossing takes place in a way that makes it impossible for us to create a collision with a wrong maneuver. That we typically wake up just four or five miles out, and typically make a sudden, panicked maneuver which is usually wrong."​

The trouble is, he's 100% correct! My knowledge of shipping is mainly as an investor, but it does give me an opportunity to see what these guys actually have on the bridge and pose our yottie questions directly to captains. Here's how the ship captains I have spoken to see it (Maersk principally):

The RYA notion of 24 mins thinking time is based upon a closing speed of 15kts, a clearly stupid number. In 2010 when the cost of ship fuel bounced from about $300 to $700 a ton the concept of "slow" and "super-slow" steaming (16-21kts) was introduced to save fuel. A side effect of this was to tie up an additional c.15% of the global shipping fleet at and dramatically change the supply lines of the big shipping companies and the industries that use them. With fuel cheap once more there is no signs of a reversal of slow steaming, but ships are now routinely speeded up to hit their arrival slots. Speeds of c.20-2kts should therefore be expected and as luck would have it many of the passenger liners are designed to operate at such speeds. So let's use 22kts as our baseline ship speed, being aware that speeds of 27-30kts cannot be ruled out.

Now to the speed of the yacht, which the RYA always seems to use 6kts. 7kts is often a better speed for an average boat whopping along in a reasonable wind, so let's use 7kts as a yotty baseline.

Doing the vectors reveals that these two vessels (22kts and 7kts)at 90 degrees to each other will have a closing speed of 23kts.

As Dockhead says the larger ships want their CPA sorted at 3miles out, 2 miles absolute, or as we say in Dublin absof**kinglute minimum, the emphasis to capture the gravity of the situation! Now ask yourself when you really start taking bearings with a bobby little hand-bearing compass/binos; 6 miles? of course not, the angle change is far too small way out there. So let's go with an optimistic 5 miles. This implies just 2 miles until the ship is on high-alert, and at a closing speed of 23kts, that gives the sailor about five minutes to fully sort his calcs, nothing like the RYA's 24 minutes!

Now let's be honest; how many of you seriously have your hand-bearing compass calcs fully sorted at three miles out, say mid-Channel in a bouncy F4? The answer has got to be none of us, apart perhaps from the bino-geeks with £5k stabilised kit.

The deduction therefore is that there is functionally nothing we can do to either help ourselves or comply with the collregs. To add empirical evidence to this deduction by logic, ask yourself how many times on the Channel do you monitor ships for an age, perhaps even make the odd course adjustment and the ship slides sweetly by about 1 mile in front, or behind you? Think of it, you can always read the name (just), read the containers with binos, see the bridge, etc; that's because it's always about a mile and that's precisely what the ship's crew dialed into their far far superior gear!

Finally some advice from the ship's captains:
1. Fit an AIS transponder so they can instantaneously see what you are doing and you them. This will stop all of the pointless and dangerous maneuvers which sometimes see yachts effect 90 degree turns to starboard, putting the boat directly under the bows of a vessel which had also altered to stbd in order to pass 1 mile behind. This sounds very much like what happened to the OP.

2. If you're stand on, then stand-on without very good reason.

3. Don't do lot's of dicky little course changes too early without knowing exactly what they will do

4. Have a decent speaker in the cockpit and and Ch 13 on dual watch. The shop will rarely want to call you, but if he does it's just a question of tapping you on his integrated display, pressing call and hey presto you're talking.

5. When and if you do call the ship ONLY EVER make two types of communication: (a) I am yacht xyz intending to do abc, do you agree? or (b) I am yacht xyz, what are your intentions? The English love the unconditional; "perhaps old chap you could move a bit to port if that's not too much trouble" . This is lovely, but at nightmare at sea.

And finally,sorry for going on a bit - fog bound!

Interesting the mention of ch13 again.
I've only used ch16, which if listened too, is the channel most ships talk on when advising intentions.

 

[Dockhead]

Interesting the mention of ch13 again.
I've only used ch16, which if listened too, is the channel most ships talk on when advising intentions.

I set a dual watch on 13 when I'm offshore, but my experience is consistent with this. Not once have I ever raised a ship's bridge on 13. In my experience they only respond on 16, and fairly often not even on that.

Has anyone called a ship on DSC? I don't think I've ever got a response that way, either, which surprises me, since I would think that their VHF sets would set off a pretty loud signal for an incoming DSC call.

And -- I know more than one ship's master who admits to simply ignoring VHF calls from yachts.

 

[BrianH]

Absolutely. It would be a disaster, I think, if recreational sailors were expected to do that.

In fact, many do not even complete the dimensional data that is entered with the MMSI identifier and stored for permanent static data transmission. Often I have interrogated a Class B target to see length and width as "0". Others prefix the name with "SY" or "S/Y" when they have already entered "Sailing Vessel" in the 'Ship Type' field. The least data for manual entering the better, it would seem.

 

[Sea Devil]

I set a dual watch on 13 when I'm offshore, but my experience is consistent with this. Not once have I ever raised a ship's bridge on 13. In my experience they only respond on 16, and fairly often not even on that.

Has anyone called a ship on DSC? I don't think I've ever got a response that way, either, which surprises me, since I would think that their VHF sets would set off a pretty loud signal for an incoming DSC call.

And -- I know more than one ship's master who admits to simply ignoring VHF calls from yachts.

I am almost certain that merchant ships do not use DSC but all do monitor 16 and frequently go down to 6 to exchange information and decide on the safest course.

We got badly frightened a couple of years ago in the straights heading for Morocco when in very thick fog radar showed a ship bearing down on us. We got no reply on 16 using its lat - long and course and eventually it passed ahead of us by around 100 metres.. Maybe they just didn't want to talk to a yacht.....

Having been scared enough to reach for my cc and install an AIS trans/receiver ( see our night and day nav / com equipment at the helm, as we sail 2 handed, is here in the pics on the right of the page http://www.michaelbriant.com/paw_paw.htm) I have found that calling a ship on 16, using it's name, has never failed to get a reply and the AIS tells me the distance off the vessel will pass or not so we avoid unnecessary transmissions. During this summers 2500nm cruise we were frequently in or near traffic lanes and 3 times we chose to call up merchant ships to ask their intentions and were treated with courtesy. http://www.michaelbriant.com/cruise_1995.htm. Approaching Messina straights VTS had our AIS on their screens already and were helpful and courteous.

Just like a few years ago when sailing with GPS stopped all other sorts of navigating the use of Radar with MARPA was probably even more important than a spare GPS. Now that AIS is here to stay and all ships establish communications on 16, sailing in or near traffic lanes, AIS is an essential bit of equipment and stops unnecessary VHF transmissions.

All that is just my opinion of course, but at the same time I miss the days and nights I used to 'navigate' my boats, without any electronics, and made an effort to keep out of the way of big ships!

 

[prv]

I set a dual watch on 13 when I'm offshore, but my experience is consistent with this. Not once have I ever raised a ship's bridge on 13. In my experience they only respond on 16, and fairly often not even on that.

I've only called a ship for collision-avoidance once - mostly, as dom says, they "mysteriously" slide past at a consistent distance while I hold my predictable course (mid-Channel we're almost always on autopilot). But on that occasion the CPA was a bit smaller, just small enough to make me nervous, and I decided to call to check that he had seen me and was ok with how we would pass.

No response to several calls by name on ch16, but an instant reply on 13 where he confirmed the same CPA figure (must have been by ARPA as we don't transmit AIS) and that we should both maintain our course and speed.

Pete

 

[dom]

Now if one accepts that ships routinely act early; let's go back to the question of why so many ship captains regard us lot as WAFIs. Stick their captain's hats on for a moment and consider your reaction to reading:

1. Threads on here which debate the finer legalities of whether a modern yott + engine is duty bound to fire-up the wretched thing when crossing a TSS
2. The threads where us yotties claim that, on the basis of our introspected interpretation of the IRPCS, we can pretty much do as we like in the zones between TSSs.

Your reaction to both of these discussions might be, "FFS guys; get a life and if you want to keep it just drive your god damned vessels at right angles and at a constant speed in all of these areas if possible. And if you're transiting a non-TSS zone which us lot and Joburg Trafficthink colloquially think of as a shipping lane, then please do so at constant speed and with an AIS tranceiver to give us a clue as to your movements!"

 

[Dockhead]

I've only called a ship for collision-avoidance once - mostly, as dom says, they "mysteriously" slide past at a consistent distance while I hold my predictable course (mid-Channel we're almost always on autopilot). But on that occasion the CPA was a bit smaller, just small enough to make me nervous, and I decided to call to check that he had seen me and was ok with how we would pass.

No response to several calls by name on ch16, but an instant reply on 13 where he confirmed the same CPA figure (must have been by ARPA as we don't transmit AIS) and that we should both maintain our course and speed.

Pete

Good to hear. I'll keep trying 13.

I don't call up ships very often. They don't like idle chatter.

 

[capnsensible]

Good to hear. I'll keep trying 13.

I don't call up ships very often. They don't like idle chatter.

Called a big ship once in mid Atlantic. They very kindly got a football result for us. Chatted for 10 minutes or so.

Was hailed by a ship near Lanzarotte on another occasion. Chap wanted a chat about yachts.

Now clearly none of this would happen in busy areas but some ship drivers are quite sociable.

 

[geem]

Called a big ship once in mid Atlantic. They very kindly got a football result for us. Chatted for 10 minutes or so.

Was hailed by a ship near Lanzarotte on another occasion. Chap wanted a chat about yachts.

Now clearly none of this would happen in busy areas but some ship drivers are quite sociable.

We were once 500 miles west of the Cape Verdes when we saw a large tanker approaching us. He came on the radio wanting to chat. Said he didn't often see yachts out in this part of the Atlantic and want to know where we were going. It turns out he was going to Middlesbrough With a tanker full of oil. My wife asked him if he was Welsh. He laughed and said he was Indian but they normally sailed to Milford Haven so he probably had a Welsh accent...The Ship was called Atlantic Berg.