yet another YM question

[Phoenix of Hamble]

Given that I enjoyed the last one, and AWOL suggested that he preferred Col-regs discussions /forums/images/graemlins/grin.gif, try this.......

You are out in the channel making 6kts, heading towards France, on your second crossing of the year. You find yourself much more confident, as last week you purchased and had installed your first Radar. You have even been on a course so that you feel confident in its use.

Imagine your sense of relief in purchasing the radar when mid channel, the visibility starts to close in a bit. Its not bad, but that characteristic halo around the mast head gives it away a bit.

You notice that the radar is showing a contact at 70 degrees on the port bow, and a range of 8nm, so you hand the helm to the crew and go below to track it properly...

After a few minutes, the contact seems to be on the same heading, but now is at 5nm, so you brief the crew to look out carefully, but you can't see it yet, and the visibility doesn't seem to have worsened.

A few minutes later, the contact remains on the same track, and is now at 2nm.

What are you going to do?

 

[fireball]

Check the AIS display ... /forums/images/graemlins/tongue.gif

 

[ChrisE]

Aim at targets bum. Sod peeing about with sails etc just organise the boat so that make it happen. Just seen that it is creeping up on quarter, revised answer think carefully, seems to be crossing the channel in the same direction as you. So sharp and fast turn to starboard at 2 miles distant you've got 5 mins to get well out of way of said craft. Probably a X-channel ferry who knows where you are anyway
Next question?

 

[Evadne]

It appears to be heading straight towards you at 50 knots (depending on how many minutes "a few" is, 1 mile per minute is 60mph) so it is either a big mobo or a ferry. Too slow for a low flying aeroplane or helicopter, too fast for a metallic seagull. At this range there is little you can do to avoid it, so hand out the lifejackets and hold your course and speed.

 

[dom]

Normally if you can see then aim at targets tail end. Problem here is - and I assume plots enabling a vector calculation have not been recorded - this would be very dangerous. The vessel could be anything from closing from 90 degrees off port bow to a reciprocal bearing just a little bit off to port! This would put you under his bow.

I would therefore brief crew etc to:

1. Start engine at low rpm put on life jackets and ready liferaft.

2. Send a crew member a little forward where it is quieter to listen and look.

3. Turn 45 degrees to starboard and slow down. I know that if the ship also moves to starboard this would require another action but as he is stand on - in a sense fog etc etc etc - hopefully he won't move.

4. If he does one would have to react by going back onto original course and increasing speed.

 

[copterdoctor]

Turn the radar off.

 

[Phoenix of Hamble]

If we assume that it appears to be doing about 20kts, then would that help? (ie.... its not a flippin helicopter /forums/images/graemlins/grin.gif)

 

[Sans Bateau]

If the target is crossing the shipping lanes as well, it probably is a X channel ferry so most likely will have seen you and will pass well clear. But...

If in doubt try calling on the VHF or as a white smoke would be pointless in the fog, how about firing a red para in his direction? That could very well clear the fog bank and alert the bridge of the impending danger.

 

[Phoenix of Hamble]

The vessel has remained at a constant bearing on the radar, so its course can be precisely understood.... it is off your port bow on a converging course, or alternative you are fine on its starboard bow....

 

[ChrisE]

Fine, back to first answer. 70 degrees relative then?

 

[Sixpence]

Oih bignose , I've only just got my head around the ' You're in the crap with little power to get out of it so head deaper into it and loose what power you have got ' idea
Now you start another one , how am I supposed to keep up /forums/images/graemlins/grin.gif

Actually these threads are perfect for me as a total novice and more use than what I normally find in here , nice one /forums/images/graemlins/wink.gif

 

[Sans Bateau]

Now knowing that, just slow down, even hove too until he passes in front.

 

[Phoenix of Hamble]

Well, the initial reaction would be to suggest that you are stand on... a potentially dangerous strategy in any conditions...... but you still haven't seen him visually, so in this case Rule 19 applies for vessels identified by radar alone.... and he therefore is not give-way vessel any more than you are stand on......

So in theory you should turn to starboard.....

The danger I see in turning to port towards his stern, is that if he has seen you on his radar, then he may well also turn to starboar, so a turn to port in your own case could make matters worse, not better.....

Thoughts?

 

[Phoenix of Hamble]

You knew that already.... all the info was there in the original post!

 

[peterb]

Does no one know Rule 19(d)?

"A vesselwhich detects by radar alone the presence of another vessel shall determine if a close-quarters situation is developing and/or risk of collision exists. If so, she shall take avoiding action in ample time, provided that when such action consists of an alteration of course, so far as possible the following shall be avoided:

(i) an alteration of course to port for a vessel forward of the beam, other than for a vessel being overtaken;

(ii) an alteration of course towards a vessel abeam or abaft the beam"

So either turn to starboard or heave to and allow the other vessel to pass.

But be careful. Most vessels going down-channel will be following the line of the TSSs. This should mean that you meet them before you get to mid-channel. This one appears to be going against the flow of traffic, so keep a good eye on the radar in case he does something funny. Oh, and keep your radar in a stabilised mode, either north-up or course-up.

 

[Phoenix of Hamble]

/forums/images/graemlins/grin.gif

 

[DeeGee]

Given her speed is 20, and ours is 6, your 'few minutes' comes out to be about 7 mins, in which time we do two lumps of just over half a mile, so she is on a course of about 270 deg relative. Best thing is a right turn to starboard for 5 mins, then come back on course.

 

[deep denial]

you're on a collision course in restricted visibility. there is no stand on vessel, and he hasnt seen you anyway. turn 180 degrees and leave the scene pronto

 

[ChrisE]

This is a case where it's bollux to the rules, GRP gives way to metal.

Don't forget that both parties have the obligation to aviod a collison and assuming that the tihng that is bearing down is big, the trace on the radar will tell you that usually, the vessel won't be able to move onto your track even it wanted to.

So you have done your bit by making signalling your attentions by effectively doing a right angled course change which will show up easily on any bridge radar's ARPA or mk 1 eyeball.

 

[Stemar]

I haven't done the vector calculations (sitting at the computer, I'm too lazy - different if it was my neck on the line), but my gut feeling is that this is a westbound ship which will pass several hundred yards ahead of my present position, just where I'll be if I don't do something about it.

Just in case it decides to do something about me, I wouldn't turn to port, so I think it's start the engine, turn about 120 degrees to starboard and scuttle off as quick as I can, watching the radar plot like a hawk. I'd also consider losing the genny to aid maneuverability in case the bugger looms out of the mist.

All this from my vast experience of a couple of channel crossings as crew, none as skipper, so constructive criticism welcome!