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

Dockhead said:
At this stage, purists will tell you to stay away from the radio, but I disagree. PROVIDED you have at least an AIS receiver and can hail the vessel by name (if not, then I agree, it's a waste of time and possibly a dangerous distraction). Hail the vessel by name and ask them if they intend to hold course and speed, or even ASK THEM to hold course and speed, and inform them about what maneuver you will take.
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+1

I think the MCA are out of step with normal practice on this.

Whoever designed the GMDSS clearly agrees with us not them, otherwise why does ch13 exist? :)

Dockhead said:
Watchkeeping on commercial bridges varies a lot, and is sometimes very poor. You will have a somewhat better chance of being seen at night with a good radar reflector, but to be recognized as participant of traffic worth paying attention to, you really need to be broadcasting AIS. AIS is now widespread enough that -- pure human nature -- vessels not transmitting AIS are noticed less and less and less. Word to the wise.
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I used to advocate an active radar transponder over AIS transmit, but reading things like MAIB reports and CHIRP increasingly supports what you're saying here. There seem to be a lot of watchkeepers out there assuming that the AIS plot is a perfect representation of reality - human nature, as you say, when presented with such a temptingly clear and simple picture. I think I would now choose AIS transmit over a radar transponder if I were to upgrade to either (albeit partly because I have no easy location for the latter).

Pete
 
prv said:
. . . I used to advocate an active radar transponder over AIS transmit, but reading things like MAIB reports and CHIRP increasingly supports what you're saying here. There seem to be a lot of watchkeepers out there assuming that the AIS plot is a perfect representation of reality - human nature, as you say, when presented with such a temptingly clear and simple picture. I think I would now choose AIS transmit over a radar transponder if I were to upgrade to either (albeit partly because I have no easy location for the latter).

Pete
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I've noticed this bad tendency in myself. I mean, discounting and not paying enough attention to radar returns not accompanied by AIS carets. You get used to every target of significance showing AIS and start to subconsciously figure that anything not broadcasting AIS can be dealt with later.

Part of it is that it is a fair amount of work to do a plot on a normal radar return, whereas an AIS target shows everything instantly, and with far more precision than you can ever plot on our pathetic recreational radars. Ships' bridges are also short handed these days quite often, so the same thing applies there, although, of course, they will usually have an effective ARPA system, incomparable to our useless MARPA systems.
 
Dockhead said:
It's a good question, the correct answer to which I think relatively few of us know.

First of all, follow the rules. Assuming you are dealing with a normal commercial ship steaming at 12 to 18 knots, the process goes like this:

Detection. Be aware of the presence of another vessel and detect a possible collision course at least 7 to 10 miles off in open water.

Stand on if you are the stand on vessel. Give the other vessel a chance to maneuver -- you are obligated to do this, in order not to screw up his maneuver.

If you do all that and by approximately 5 miles out there has been no alteration of course or speed by the other vessel, then in many cases you may reasonably assume that no action will be taken, and you have the right to maneuver yourself.

At this stage, purists will tell you to stay away from the radio, but I disagree. PROVIDED you have at least an AIS receiver and can hail the vessel by name (if not, then I agree, it's a waste of time and possibly a dangerous distraction). Hail the vessel by name and ask them if they intend to hold course and speed, or even ASK THEM to hold course and speed, and inform them about what maneuver you will take.

Then, make a large change of course which leaves no doubt to observers about what you are doing. Avoid turning to port if possible. To do this safely, you need to be able to know how you are crossing with the other vessel, so you need to be handy with a HBC or radar plot, or much better, HAVE AIS. Otherwise, you might not recognize a safe pass already organised by the ship, and turn into a collision course. You can't tell just by eyeballing it -- you must have one of these methods.


That's it.

By the way, you should not assume that ships see your nav lights. Watchkeeping on commercial bridges varies a lot, and is sometimes very poor. You will have a somewhat better chance of being seen at night with a good radar reflector, but to be recognized as participant of traffic worth paying attention to, you really need to be broadcasting AIS. AIS is now widespread enough that -- pure human nature -- vessels not transmitting AIS are noticed less and less and less. Word to the wise.
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Thanks for very clear advice. Its so useful to get the view from the bridge.

I figure if I am standing across an average MV with a speed of, say 15 knots, then we got 1 mile in 4 minutes. I get him at, say, 6 miles. 24 minutes left to make my mind up. Im sailing, mebbe close to the wind. 10 minutes later, even if our closing speed is 8 knots, its still an easy call. It aint driving a car on a motorway or turning right at the lights! I struggle with that, poor driver!

But assessing ROC is simple when you follow the easy rules.

Just sayin!
 
capnsensible said:
Thanks for very clear advice. Its so useful to get the view from the bridge.

I figure if I am standing across an average MV with a speed of, say 15 knots, then we got 1 mile in 4 minutes. I get him at, say, 6 miles. 24 minutes left to make my mind up. Im sailing, mebbe close to the wind. 10 minutes later, even if our closing speed is 8 knots, its still an easy call. It aint driving a car on a motorway or turning right at the lights! I struggle with that, poor driver!

But assessing ROC is simple when you follow the easy rules.

Just sayin!
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Well, if you're making 6 knots, and he's making 15, and you're on perpendicular courses, you are closing at 16.2 knots. From 6 miles out, you certainly don't have 24 minutes to make up your mind. If we consider a safe pass to be 1 mile (as per typical bridge standing orders), then we need to have maneuvered a few miles out, to turn a 0 CPA into a 1 mile CPA. I, personally, don't like to stretch this out much beyond 5 miles. So from 6 miles you have 3.7 to maybe 7.4 minutes, to have calculated the crossing, made the necessary plots, figured out a maneuver, and then initiate that maneuver. That time goes by awfully fast. Ergo, six miles out is pretty late to start thinking about all of this.

Absolutely crucial in this is to understand how you're crossing. If you are doing it with a HBC, then you will need some time to take a series of bearings. And the best HBC plot will not really tell you +/- a mile, so you will need more than a mile of margin of error, and you will have to maneuver even earlier.

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.

They call us "WAFIs".
 
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Well, I am a professional mariner. Quite a lot of my working day is demonstrating how to asses the risk of collision and how to take appropriate action.

Crossing shipping lanes will generally give the opportunity to determine visually and by ais a CPA. One mile is adequate as you say. You got 20 minutes to make your mind up with a good lookout It is very straightforward. The 30 knot ferries require a tad more thought but anticipation and a willingness to take early and appropriate action works.

After all, you can still call them on the vhf........
 
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!
 
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I found your post interesting, Dom.

A look at a site like marine ais reveals that the average speed of cargo ships and tankers is about 12 to 15 knots. Of course some are quicker, as I mentioned, some ferries do 30 knots.

There is always plenty of time with a good lookout. Im lucky to get to cross two busy shipping lanes on average twice a week. My 20 minutes is an average based on hundreds of real observations.

Ships are relatively predictable for small vessel sailors, hence collisions are thankfully very rare.

Interest value is greatly enhanced when tacking your way through a Moroccan fishing fleet....... :ambivalence:
 
capnsensible said:
I found your post interesting, Dom.

A look at a site like marine ais reveals that the average speed of cargo ships and tankers is about 12 to 15 knots. Of course some are quicker, as I mentioned, some ferries do 30 knots.
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Agreed, and that is indeed the mean speed, but without AIS/ARPA I'm suggesting 22kts as a baseline ship speed for calcs
 
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dom said:
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!
Click to expand...

I think this is all spot on. A minor quibble -- I agree with Capnsensible that you rarely see ships these days steaming above 20 knots. Usual speed is 15 to 18. But that doesn't at all change your conclusions, which are right in my opinion.

What you say can be boiled down to this, which is actually more extreme than what I said -- if you want to meaningfully participate in traffic, rather than being mere flotsam, you need to have AIS, because what you can do with a HBC will not give you enough information, early enough.

I think that's generally correct. A good radar operator using one of the less execrable of the recreational radars on the market can do much better than a good HBC operator, but it it a good bit of work, so not all that realistic for a short-handed yacht, even if the skills and equipment are on board.

Why bother when an AIS receiver can be bought for a couple hundred quid, complete with splitter?
 
I'll repeat a point I tried to make earlier in this thread; as far as I know it is not possible by AIS alone to determine whether a Class B target is a vessel sailing, motor sailing or motoring. If we are now encouraging all to use AIS as the primary means of collision avoidance we must all behave as PDVs irrespective of our actual means of propulsion - which conclusion surely starts to make a nonsense of col regs as currently written ?
 
RobbieW said:
I'll repeat a point I tried to make earlier in this thread; as far as I know it is not possible by AIS alone to determine whether a Class B target is a vessel sailing, motor sailing or motoring. If we are now encouraging all to use AIS as the primary means of collision avoidance we must all behave as PDVs irrespective of our actual means of propulsion - which conclusion surely starts to make a nonsense of col regs as currently written ?
Click to expand...

That's why God made motoring cones, and steaming lights. In daylight, he can see your sails, and if there's no motoring cone, you are a vessel under sail. At night, the absence of a steaming light shows that. He doesn't need AIS to know that you are under sail.

If for whatever a ship's bridge fails to determine that you're under sail, and behaves as the stand-on vessel (or for that matter, fails to see you altogether), this is no problem at all if you are following the rules. At the point where you can see that he is not maneuvering, you have the right to maneuver yourself. Do so in time, and problem solved. For me, that happens at about 5 miles. Having AIS will give you instant data about which way you need to turn, so that you can be sure that you are not turning into a collision.
 
>I'll repeat a point I tried to make earlier in this thread; as far as I know it is not possible by AIS alone to determine whether a Class B target is a vessel sailing, motor sailing or motoring. If we are now encouraging all to use AIS as the primary means of collision avoidance

That's why we never had AIS the Mark One eyeball can tell what any vessel is and whether under power or sailing plus whether it's a collision risk.
 
Dockhead said:
That's why God made motoring cones, and steaming lights. In daylight, he can see your sails, and if there's no motoring cone, you are a vessel under sail. At night, the absence of a steaming light shows that. He doesn't need AIS to know that you are under sail....
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For sure; earlier in the thread you or someone else made the point that lights are 'useless' as often not seen from the bridge so the absence or otherwise of a steaming light is unlikely to make a difference in that instance. We are also being told that big ships want to make course changes early and we may not see those, if those decisions are made at 10 miles I'd argue its unlikely the ship has actually identified its target as a sailing vessel and is turning on the basis of PDV rules.

I'm well aware of what I should be doing as a sailing vessel to be identified correctly. What is less clear is how a vessel with which there is an 'roc' can properly identify the action it should take at 10 miles, even at 5 in indifferent visibility.

Taking capnsensible's comments, once we (as yacht skippers) are aware of the roc we need to ensure our craft is maneuverable. If that means removing poled out jibs, dropping kites, calling out the crew (or other person on board), removing preventers etc then thats what we have to do.
 
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Dockhead said:
I think this is all spot on. A minor quibble -- I agree with Capnsensible that you rarely see ships these days steaming above 20 knots. Usual speed is 15 to 18. But that doesn't at all change your conclusions, which are right in my opinion.

What you say can be boiled down to this, which is actually more extreme than what I said -- if you want to meaningfully participate in traffic, rather than being mere flotsam, you need to have AIS, because what you can do with a HBC will not give you enough information, early enough.
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15-18kts is certainly the normal planned slow-steaming speed. However, with oil prices where they are now, a number of operators, including Maersk have added to their logistic parameters the ability to bump the speed up to c.21kts to hit a delivery point. So and on that basis 21kts is not outside the expected speed envelope.

Where I think we're in agreement is that AIS, at a few hundred quid, is now a de facto necessity for any vessel frequenting the Western European shipping channels. To quote a ship's captain here, the rest of us are "well meaning dreamers"! Now I've no idea how many ships sport AIS on the approach to Vladivistok, but in our part of the world it's got to be worth a thought.
 
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This thread seems to be losing some sense of proportion!

There are hardly ever any collisions. Why? Big ships are easy to avoid in small boats. They are predictable. mostly.

15, 20 knots, doesn't matter, you still got plenty of time.

Its not rocket surgery!

Of course AIS and radar are useful tools, especially when visibility is poor, but even then collisions are rare.

Practice, practice, practice the same as all facets of our sport. :encouragement:
 
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RobbieW said:
Taking capnsensible's comments, once we (as yacht skippers) are aware of the roc we need to ensure our craft is maneuverable. If that means removing poled out jibs, dropping kites, calling out the crew (or other person on board), removing preventers etc then thats what we have to do.
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The point I am making here is that when it comes to that type of ultra-maneuverability, one is probably in a place one never ever wants to be, or indeed needs to be. AIS can go a heck of a long way to help one calmly avoid close contacts.
 
capnsensible said:
This thread seems to be losing some sense of proportion!

There are hardly ever any collisions. Why? Small boats are easy to avoid in big modern ships. They are predictable. mostly.

15, 20 knots, doesn't matter, you just have to act in time.

Its not rocket surgery!
Click to expand...

Agreed! Apols for cheeky editing! ....happy to delete if in any way offensive :D
 
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