Originally Posted by Dockhead (Post 2507238)

What does the following ship have to do with the cross between two ships at high speed?

Seriously?

Obviously, there is a need to miss hitting the lead ship AND the following ship.



Wow, you are still trying to use strawman arguments. Amazing.

I never ever ever said it was "safe" to attempt this crossing at all. And of course, what is "safe" is subjective. There's a big difference between "safe" and "successful".

It is highly unlikely anyone would consider this maneuver "safe". However, I certainly consider the one that gets across the other side (me) is much safer, and more "successful" than the one that gets nailed by the following ship (you) if the ships maintain course and speed.



Nope.

And not the point at all. The point is that the 3 cable CPA you proposed behind the lead ship was not safe, AND you got nailed by the following ship. Did you not get that?



Seriously?

You are crossing between two ships. Anything you do to affect distance from one, also affects distance from the other.

If you navigate in congested waters, only looking at how your maneuvers affect your relationship with one vessel, well I'm surprised as heck you are still here.



First of all, the scenario was based on the ships not responding to communications. There is nothing magic that makes the 180 CPA a "collision course" and the 3 cable CPA not. In either case, the bow of the sailboat is pointing ahead of the bow of the ship (initially) and the distance between is closing rapidly. In the end, your 3 cable CPA leaves you running into the following ship.

Bang, Glug Glug Glug.



You can setup a CPA of 0 with the stern of the lead ship if you wish.

180 ft CPA is not a "collision course". If the CPA is maintained and the ships maintain course and speed, there is no collision.

The 3 cable CPA you proposed is a "collision course". You will most definitely hit the vessel following, even if the plan is executed flawlessly.

Originally Posted by TJ D (Post 2507353)

I've said this a few times, but nobody seems to have picked up on it.

Rod was suggesting this 180' stuff LONG before the 'line of ships' scenario was introduced. He was talking about doing it right from the start, and then invented the scenario afterwards to support this 180' business.

It was being presented to us, forcefully, as safe and appropriate if only your 'pucker factor' was high enough.

The line of ships thing came later, presumably as cover for a reckless contention made prior.

Originally Posted by ramblinrod (Post 2507060)

>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>>

I'm sorry you had such difficulty rounding a moving target in close proximity. I would have had to see it, to understand what you did so terribly wrong.

Originally Posted by Stu Jackson (Post 2507476)

Thanks for responding. I've been on the water all day, just pulled in. Haven't caught up completely yet.

However, I would appreciate your observations on what I did "so terribly wrong" given my post which I thought explained it, and why he was long gone by the time I "got there."

Thank you.

Originally Posted by TJ D (Post 2507353)

I've said this a few times, but nobody seems to have picked up on it.

Rod was suggesting this 180' stuff LONG before the 'line of ships' scenario was introduced. He was talking about doing it right from the start, and then invented the scenario afterwards to support this 180' business.

It was being presented to us, forcefully, as safe and appropriate if only your 'pucker factor' was high enough.

The line of ships thing came later, presumably as cover for a reckless contention made prior.

Originally Posted by ramblinrod (Post 2507913)

Already answered.

I would have had to see it, to understand what you did so terribly wrong.

Originally Posted by Exile (Post 2507343)

The basic point being that whether it requires superhuman powers or a high pucker factor, and whether or not you'd be toast, it violates multiple provisions of the Colregs, is unquestionably unsafe, and defies common sense & rudimentary logic. And these are single ship scenarios I gather in open water.

So it all begs the obvious question: Why do it? And maybe the slightly less obvious question: Why propose doing it, or even suggest doing it on a thread involving serious discussions about real-life collision avoidance? Except as rational posters have done here, namely as a hypothetical learning exercise to demonstrate why it should never be attempted.

Originally Posted by TeddyDiver (Post 2507919)

So doing what you've been promoting is terribly wrong? :flowers:

Originally Posted by ramblinrod (Post 2507918)

The earlier reference to 180 ft, was with regard to holding stand-on when approaching a give way ship at 90 degrees, until 1/4 nm away, to give them ample time to execute their plan, and not interefere with their plan, should they have been holding off execution for some good reason.

The line of ships scenario is a different discussion other than it also has to deal with a ship crossing situation.

Originally Posted by ramblinrod (Post 2507923)

Why have the conversation?

Because:

a) We were discussing crossing situations.
b) We were discussing risk aversion.
c) We were discussion whether "safe distance" is subjective or objective.

I do have to say at this point, after all of this discussion by many posters, to ask why we have discussed it all, is pretty irrational.

It was discussed, because so many wished to discuss it I s'pose.

Originally Posted by Exile (Post 2507933)

But as to the earlier reference, you advocate waiting until 1/4 nm away to allow the give way vessel "to give them ample time to execute their plan, and not interfere with their plan??"

Oh but wait, you've suddenly changed the facts . . . now "they have been holding off execution for some good reason." :

Originally Posted by ramblinrod (Post 2507293)

OK, I think we've been through all this before. It looks like the argument goes like this:

"180 foot CPA with a fast ship is dangerous -- too close to attempt to pass."

"No it's not. If you pass with a greater margin, you run into the ship behind."

"Maybe you run into the ship behind, but it's still not safe to attempt to pass so close to the ship ahead."

"If you pass further, you run into the ship behind."

"What does that have to do anything? If that's true, then you can't pass at all!"

Originally Posted by Exile (Post 2507343)

Why do it? And maybe the slightly less obvious question: Why propose doing it, or even suggest doing it on a thread involving serious discussions about real-life collision avoidance? Except as rational posters have done here, namely as a hypothetical learning exercise to demonstrate why it should never be attempted.

Originally Posted by ramblinrod (Post 2508066)

Already answered.