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  #21  
Old 03-31-2011
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Quote:
Originally Posted by jackdale View Post
Get on the radio and figure out what their intentions are.
Gee.. 20 posts on this topic already and not a single mention of AIS!?!

In this day and age, if you want to know what their intentions are in plenty of time to do something about it, no-one should go to sea without AIS...
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  #22  
Old 03-31-2011
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Since this is a "discussion", three thoughts came to mind when reading the OP.

1. awesome algebra!
2. the dreaded partially submerged ship's container collision hazzard isn't accounted for. Despite a theoretical sight distance calculation, given any wave height, you wouldn't see it until you had seconds to avoid it. SOL almost entirely at night.
3. a breaching submarine isn't either, although, I suspect they are more aware of your presence than you are of theirs. Just an interesting thought. BTW, I haven't seen one since I was a kid, but was off the backside of Fisher's Island in LI sound when it felt like it breached within throwing distance. I'll bet it was a mile away though. I was probably about 12 years old.
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  #23  
Old 03-31-2011
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Quote:
Originally Posted by seafrontiersman View Post
I go to sea for a living and I can tell you that on commercial vessels, Rule 5 (as interpreted by USCG, insurance carriers, and various international governing bodies) DOES require a constant visual lookout by a person who is not actually steering the vessel. This is heavily referenced in the STCW course "bridge resource management" not trying to be pedantic, just stating the facts...

As a single/short handed sailor, I also realize that this is simply not practical on all vessels at all times.
It absolutely should require a constant visual lookout for commercial vessels. Given the manning available there is no excuse for less.

The impracticality of the same interpretation for a single/short-handed sailor does not mean said sailor is in violation of the rule but is unable to reasonably comply ... it simply means that the interpretation of the rule is dependent on the specific situation (which is exactly why the rule includes so many qualifiers...). But ... a debate on the semantics of the rule is tiresome and irrelevant to my original point ... what matters with regard to Rule 5 for the sailing situation I'm discussing (single/short-handed sailing) is the spirit of the rule, minimizing risk of collision with the available resources.

The 'look interval' I refer to has two implications. First, it lets you know how long you can go between visual sweeps. Second, it lets you know how long you can't go between visual sweeps.

Some have chimed in and claimed 20 minutes as the correct interval. Someone else said 10 minutes. I ask you, why 20? Why not 30? Why is 10 safe? Why isn't anything longer than 5 minutes putting yourself at risk? If you don't have reason to support a specific number ... then your specific number is just arbitrary. Some even claim that the safe way for a single-handed sailor to accomplish sleep on a passage is to heave to.

If this fancy super-freighter moving along at 40kts is coming towards you then it will cover 13 nautical miles within a 20 minute interval. If you are cruising along at 7.5kts then you will close another 2.5 nautical miles and you'd better hope you can see that contact further than 15.5 nautical miles away.

So ... we make the interval 10 minutes ... and we are still single handed. You try to maintain lookouts every 10 minutes but ... damn it, you're a human being ... and instead, after maintaining this ridiculous schedule for 3 days, you fall hard asleep for 2 hours. You're at risk of collision from anything on the water if you pass out for two hours.

You heave to, cut your own forward progress to 0.5kts, and go below to sleep for 2 hours. You're still at risk for collision from anything on the water. 2 hours is enough time for a 12kt freighter to cover 24 nautical miles and I promise you that you won't see a freighter from 24 nautical miles away before you tuck yourself in. The fact that you cut your own ground speed to almost nothing has very little effect on your safety from collision.

These are all situations of how long you can't take your eyes off the horizon.

You've been standing watch continually for the past 8 hours, you're in the tropics, sailing in 8 kts of breeze downwind, and if you don't get below for a cold beverage and a few minutes in front of the fan in the shade then you're seriously considering heat stress. How long can you take your eyes off the horizon?

You thought you were going to be standing port/starboard with your other shipmate. Unfortunately, 400 miles off the coast they decide to eat the wrong thing and now they are lying in the fetal position on the cabin berth. Now ... you're single handed. You're getting pissed that they can't even get up long enough to fix you a meal ... and now you're starting to feel sick to your stomach. How long can you afford to hit the head?

If you head down for 20 minutes should you be filled with paranoia and punish yourself for being such a shoddy seaman? Maybe, maybe not ... it depends on how long you can take your eyes off the horizon and there is a reasonable way to determine that.

A short-handed sailor needs to be able to make compromises. Compromises based only on superstition or guesses aren't very confidence inspiring and may/may not be wise compromises to make. A look interval is a tool. If you don't want to use it, what do I care? Keep coming topside every 10 minutes. 10 minutes is probably sufficient for safety (probably entirely impractical single handing) and maybe 10 minutes, given the conditions, is even often enough to keep you safe. Wouldn't you like to know that? I guess not.
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  #24  
Old 03-31-2011
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Quote:
Originally Posted by scraph View Post
It absolutely should require a constant visual lookout for commercial vessels. Given the manning available there is no excuse for less.

The impracticality of the same interpretation for a single/short-handed sailor does not mean said sailor is in violation of the rule but is unable to reasonably comply ........
Scraph,

I think I finally understand where you're going with this. You seem to be arguing that a single-hander or short-handed vessel is absolved from the requirement to maintain watch at all times.

They are not.

The argument you are making is a very tired one, that has been put forth again and again over the years. It attempts to find a loophole where there isn't one. There is nothing in this Rule 5, nor elsewhere, that relieves a single-hander from the requirement to maintain a watch at all times. That is why single-handing for periods beyond which a watch can be maintained at all times, violates the rules.

That said, there are long-distance singlehanders, and it's obviously not possible for them to maintain a watch at all times. Humans must eventually sleep. And that is what single-handers do -- they come up with some kind of horizon-scan schedule that they believe adequately mitigates the risk of collision while giving them a chance to sleep. It is, in essence, a gamble where they hope the odds as they've calculated them will prove favorable.

This is the risk analysis that a single-hander must make. But, when they take their nap, they are absolutely in violation of the COLREGS. There's no getting around it (not even by signaling "vessel not under command".) So, sure, go ahead and discuss watch keeping strategies for the singlehander, but don't link it to the argument that not keeping a watch is somehow permitted under the rules.
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  #25  
Old 03-31-2011
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Quote:
Originally Posted by scraph View Post
ships, height of 120ft and a cruising speed of 12kts (distance to horizon for 120ft is 13.4 nautical miles).

we are cruising along at 6 knots and from the cockpit our height of eye to scan the horizon is at 8ft above sealevel (distance to horizon for 8ft is 3.5 nautical miles).

to gain first sight of this large tanker at a
56 minutes for us to collide (16.9nm / 18kts = 56.3 min).

Yes. I think you are very correct.

Modern container ships can go 25 knots but they never do. OK one exception I saw was when one was being perused by Pirates. (see Somalia Pirate Attacks and our Conovy. Wittnessing a Pirate Attack in the Gulf of Aden near the Red Sea 2010)

MSC recently agreed that their ships go 12 to 14 knots.
Even Reefers seem never to be above that speed. Don't the Bananas go off? I guess better scheduling is the reason why ships go slower these days by still keep the same schedule.

Your figures for sighting a ship are much better than most peoples as they don't take into account for the ships mast head being higher than the bridge. At night the masthead light can even be seen as loom before it appears. During the day new ships have orange dayglo on the higest points above the bridge to aid visibility.

The only disagreement I have with your thoughts are the time to take evasive action. You state 3 to 4 miles. "us with 3.4nm of warning, we turn off our current course by 90 degrees. The time required for the tanker to close that last 3.4nm is roughly 11 minutes." I haven't seen too many ships begin to take evasive action at such a distance. Normally its within one mile.
Contrary to Colregs I don't consider a yacht much chop to be the Stand On vessel. I get the hell outta their way! But even then its well within that 1 nm, not 3 or 4nms.

The video below shows you how I can make a video when a ship is quite close. They are nothing to worry about! NOTE: Note the advice I give to the ship

"What we do when cruising" or "What we really do when cruising"


Most important imho is not to worry or get scared of ships. Learn how to avoid them and keep your eye on them. But don't let them worry you.



Mark
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  #26  
Old 03-31-2011
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Quote:
Originally Posted by JohnRPollard View Post
Scraph,

I think I finally understand where you're going with this. You seem to be arguing that a single-hander or short-handed vessel is absolved from the requirement to maintain watch at all times.

They are not.
Sir, your opinion is your own.

What is your horizontal field of vision? Maybe 120 degrees? That leaves 240 degrees at any given time that you are not maintaing lookout 'at all times' on, correct? Why isn't there a requirement that 3 people be posted, minimum, to stand a proper lookout at all times? We could certainly make such a ridiculous argument going along the lines of your interpretation of this rule. The fact is ... if you conduct a full visual sweep (by binocular) in a matter of minutes then any 'new information' happening outside your field of vision won't be left undetected long enough to increase your risk of collision. There is very little functional difference between how long something is left unseen because it is behind you and how long it is left unseen because you haven't spotted it yet.

If no vessel you can reasonably expect to encounter can close the distance to you from initial sighting to collision between visual sweeps then scanning the horizon more frequently will yield no more information to properly assess the 'situation' and to determine 'risk of collision'. If you sight a contact on the horizon, take a note of AOB, estimate range, range rate, bearing rate ... and then you do the same thing over again in a minute, every minute ... you aren't reducing your risk of collision ... you're just being nutty.

But I don't need to convince you ... this 'interpretation' of the rule is used by a certain, large group of mariners quite often ... and we are definitely not in violation of the rule in question. What if I told you that we don't even look in our stern 120 degrees constantly ... but instead only look back there on a specific interval? Are we violating the rule of maintaining a proper lookout at all times?

No. We are not. We operate in a reasonable and deliberate manner to ensure that we gather sufficient information to properly assess the situation and determine risk of collision. Looking anymore often than that does _not_ yield much more useful information. We are submariners and the lion share of our time is spent without visual available at all. We aren't simply exempt from certain rules because 'we're different'. I ensure you that we are also complying with navigational rules... heck ... we even require an exception because our stern light is attached to a movable rudder.

Having a man assigned to lookout duties with orders to conduct a full visual scan every 20 minutes is probably keeping a look out at all times. Single-handers are not absolved from the requirements to maintain look out at all times ... if they stand the watch in a reasonable manner such as this then they simply _are_ keeping a look out at all times. If the contact picture shows that 20 minutes is likely insufficient (due to nearshore piloting or higher speed vessel traffic, for example) then that same 20 minute interval would now _not_ be sufficient watchstanding.

You can interpret the rule until you're blue in the face. The point of the rule is the purpose and if scanning the horizon every minute doesn't reduce my risk of collision ... then I'm not going to scan the horizon every minute, nor do I need to.
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Last edited by scraph; 03-31-2011 at 12:04 PM.
  #27  
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Quote:
Originally Posted by MarkofSeaLife View Post
The only disagreement I have with your thoughts are the time to take evasive action. You state 3 to 4 miles. "us with 3.4nm of warning, we turn off our current course by 90 degrees. The time required for the tanker to close that last 3.4nm is roughly 11 minutes." I haven't seen too many ships begin to take evasive action at such a distance. Normally its within one mile.
Contrary to Colregs I don't consider a yacht much chop to be the Stand On vessel. I get the hell outta their way! But even then its well within that 1 nm, not 3 or 4nms.
I agree that 3 to 4 miles action might be excessively cautious. My discussion was all wrapped up in worst case scenarios ... and if you come topside to see a contact heading directly towards you then the simplest thing you can do is alter your course by 90 degrees. I figured bringing this whole thing up would get the superstitious old salts riled up ... so I hoped giving them multiple miles of sea room in my scenario would calm them It didn't. Oh well!

My method of contact management is ... take out the binoculars and figure out where he's headed, how fast he's going, and how far away he is. If I can make a small course correction now to guarantee him as an opening contact ... instead of maintaining course and deliberately steering around him later ... then I will make that small course change now and return to my original course once he's crossed aft of my beam. I very much believe in the assumption that freighters aren't steering zig zags on the open ocean. If you know what they were doing 10 minutes ago then it's a fair assumption you know what they are doing now. I'm not going to be distraught with paranoia because I haven't been staring at them constantly!

I might take 'evasive action' at a range of 10nm ... but it is likely to be only a few degrees. Take a small action early and you won't have to deliberately steer around him later.

Fair winds and following seas, sir.
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  #28  
Old 03-31-2011
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Quote:
Originally Posted by scraph View Post

I might take 'evasive action' at a range of 10nm ... but it is likely to be only a few degrees. Take a small action early and you won't have to deliberately steer around him later.

Fair winds and following seas, sir.
We teach, "Do it early and do it big."

Quote:
Action by Give-way Vessel
Every vessel which is directed to keep out of the way of another
vessel shall, so far as possible, take early and substantial action to
keep well clear.
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  #29  
Old 03-31-2011
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The Rules state: 'maneuver in Ample Time.' And that is early and the more sea room you have the safer you will be. And you all do operate under the SAFETY FIRST rule, don't you? On the bridge of said ship the standing orders is to have a 3 mile CPA. But that is with other ships. But 3 mile cpa can be a good rule to go by with ships... With smaller vessels you may want to shorten the distance, pending on their size. Say one mile for a vessel of your size up to three miles on ships. But I have seen some lousy helmsmen out there and they couldn't steer a straight course if they tried. So keep an eye on them until they are well pass and clear.
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Quote:
Originally Posted by jackdale View Post
We teach, "Do it early and do it big."
I suppose that works to. I evaluate every contact I acquire and maneuver as necessary to avoid a collision course (or just to open CPA). With sufficient understanding of the situation and how range and bearing will progress, generally only a few degrees course change are required if done early. Since I'm balancing appropriate maneuvering for all contacts (if any is required) with the fact that I'm trying to go somewhere as well ... if 2 degrees works to open CPA to 1 nm then that is exactly what I'll do. There is usually no sense in 30 degrees course change for a contact sighted on the horizon.

If they are sighted at 15nm and head on at 12kts their speed, 6kts your speed then you have 50 minutes until CPA (currently CPA is collision). If you alter course in either direction by only 8 degrees then your CPA will open to 1 nm.

Do it early, do it big sounds good ... but if you do it early, you don't at all have to do it big! We're all trying to get somewhere. No sense altering course by 30 degrees if 8 will do it! And, unless you've screwed up already ... 30 degrees is the largest course change I'd make. You put 50% of your speed across the line of sight with 30 degrees but keep nearly 90% in the line of sight! ... 45 degress, you put 70% across the line of sight but you also only keep 70% in the line of sight. We can't just bounce around the ocean like a pinball machine
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