The "Making Trees" fallacy appears again...

[nofacey]

Chotu is dead right….using an onboard reference point is reliable & far simpler

[requiem]

I do think getting into the various other methods (e.g. radar) distract somewhat from the original question about the basic geometry of the "making trees" topic.

For me, all the mentioned videos reflect a failure to understand the mechanics of the "making trees" concept. The original video selects a background reference that is far too close. The rebuttal videos get a little closer by recognizing distance as a factor, but then go astray due to not understanding why it's a factor.

Only a few days ago I saw some Reddit comments mentioning the method in the context of maneuvering within a marina. Thus, I think properly understanding the method is critical to avoid using it in inappropriate cases.

[Morris Wilson]

From flying experience I learned early if an object is not moving on your windshield (or side window) you are on a collision course. Using trees doesn't work. I use that theory when approaching an intersection with a vehicle as well. By the way, it is also the way you land a plane. once you are on a steady approach the spot on the ground that is not moving is where you would touch down if you didn't flare. It works with anything but not on an object that is turning. last minute turns need to be anticipated.

[El Pinguino]

Originally Posted by s/v Jedi

Yes, you can see if a target is coming at you. It's a newer feature and while I would skip the VRM, if I see a trail indicating that a target is coming at me, I will still put an EBL on it to get more precise info.

Also, you can use ARPA. Normally you need professional grade radars for this but then you can still get MARPA, where you have to point out the target and the radar will calculate CPA, TCPA etc.

I find that most cruisers with radar did nit get any education in the use of radar. It is mind boggling

My 25 year old Anritsu has the tails feature as did my last day job - built 1999.

[Lodesman]

Originally Posted by s/v Jedi

I find that most cruisers with radar did nit get any education in the use of radar. It is mind boggling

It's somewhat frustrating when an authority like Starpath, doesn't check their work. I figure they know what they're talking about, but I think in the name of brevity, they flubbed the highlighted point. The trails are a relative vector; by themselves they don't indicate the speed of the other vessel. The simplest example is if you are going 5kts, and vessel ahead of you is travelling in the same direction. If he's going 3 kts, the trail will show 2kts towards you. If he's going 7kts, the trail will show 2 kts away from you. Have him coming towards you at 3 kts, and the trail will look like 8kts. Can't believe they made such an elementary error.

[El Pinguino]

Originally Posted by nofacey

Chotu is dead right….using an onboard reference point is reliable & far simpler

That works fine if you are hand steering and sitting or standing behind the wheel, other wise - if you are on autopliot - not so useful.

[sailingharry]

Originally Posted by parkstone bay

There's the story of the small boat skipper who took sequential compass bearings of a bigger vessel, and found they were changing, therefore , he thought "no chance of a collision"; then he realised that the bearing of the bow of the VLCC was decreasing, while the bearing of the stern was increasing!

Ha! Been there. Used to race Chesapeake Bay log canoes. The skipper can't see much of where he's going -- too much sail in the way. So the jib trimmer (me) calls traffic. I was watching a canoe on starboard (we were on port) and calling it (using trees, of course!). It was an easy cross. Except I forgot there was 30 feet of boat behind me! The owners son on the outrigger (boomkin) could have traded high fives with the boardsmen on the crossing boat. Skipper was NOT happy! LOL

[nofacey]

Originally Posted by El Pinguino

That works fine if you are hand steering and sitting or standing behind the wheel, other wise - if you are on autopliot - not so useful.

Sorry El Pinguino, but that is so not true - where you are on board (and who or what is steering the ship) is irrelevant, as long as the boat is following a steady course and you yourself are staying stationary.
Line up the vessel in question with any fixed point aboard your boat, and stay still yourself(seated at the stern, or Port amidships or wherever…though this would be tough to do on the bow)…..if the vessel in question moves towards your bow, they’re going to be ahead of you, if they’re falling back, behind……but if they remain lined up on the selected point on your boat…..you’re going to hit.

[El Pinguino]

Originally Posted by nofacey

Sorry El Pinguino, but that is so not true - where you are on board (and who or what is steering the ship) is irrelevant, as long as the boat is following a steady course and you yourself are staying stationary.
Line up the vessel in question with any fixed point aboard your boat, and stay still yourself(seated at the stern, or Port amidships or wherever…though this would be tough to do on the bow)…..if the vessel in question moves towards your bow, they’re going to be ahead of you, if they’re falling back, behind……but if they remain lined up on the selected point on your boat…..you’re going to hit.

Sigh..... OK you have to be stationary either on the wheel or elsewhere.. no popping below to put the kettle on.

[Ronny170]

Originally Posted by Lodesman

Jedi's point is that the EBL functions in the same way that the "making trees" method is supposed to function, as it is traditionally used. If the vessel is steady on the EBL, a quick glance would show it not making trees and risk of collision exists. If it moves away from the EBL, you should see it making trees and no risk of collision exists. This all supposes you use the method correctly, not as was shown in either video. Jedi is right, no surprise.

Again, this is incorrect. If we are talking about two vessels on collision courses, relative bearing (in theory, practical measurement arguments aside) and compass bearing to target will remain constant, and it will remain steady on EBL etc, etc AND the target vessel will "make trees" at a constant rate as well, as determined by the observing vessel's speed. This really shouldn't even be part of the debate here. What was being discussed is what that forward motion or amount of "tree making" actually looks like when on collision courses, vs not on collision course.

[s/v Jedi]

Originally Posted by requiem

I do think getting into the various other methods (e.g. radar) distract somewhat from the original question about the basic geometry of the "making trees" topic.

For me, all the mentioned videos reflect a failure to understand the mechanics of the "making trees" concept. The original video selects a background reference that is far too close. The rebuttal videos get a little closer by recognizing distance as a factor, but then go astray due to not understanding why it's a factor.

Only a few days ago I saw some Reddit comments mentioning the method in the context of maneuvering within a marina. Thus, I think properly understanding the method is critical to avoid using it in inappropriate cases.

Oh, I thought we worked that out a week ago with someone pointing out that comparing bearings with time intervals is the same as the making trees method except with a tree very far away on the North Pole.
Similarly, the all accepted method of taking bearings with intervals doesn’t work when sailing past the North Pole, because now the object is too close, just like in the videos with objects ashore being too close.

OP ignores this because it immediately kills his argument that he keeps pushing for the sake of arguing

[s/v Jedi]

Originally Posted by El Pinguino

My 25 year old Anritsu has the tails feature as did my last day job - built 1999.

Yes LoL

I guess that shows how long ago I did my exams

[s/v Jedi]

Originally Posted by Lodesman

It's somewhat frustrating when an authority like Starpath, doesn't check their work. I figure they know what they're talking about, but I think in the name of brevity, they flubbed the highlighted point. The trails are a relative vector; by themselves they don't indicate the speed of the other vessel. The simplest example is if you are going 5kts, and vessel ahead of you is travelling in the same direction. If he's going 3 kts, the trail will show 2kts towards you. If he's going 7kts, the trail will show 2 kts away from you. Have him coming towards you at 3 kts, and the trail will look like 8kts. Can't believe they made such an elementary error.

It is worrisome. But not as much as half of group 8 students being analphabetic… imagine what is ahead of us with civilization rotting away

But we still have bright people as well as innovation. I believe the new consumer level radars have Doppler support and will color the trails according to the speed of the target? I imagine they could choose colors relative to own speed even?

[s/v Jedi]

Originally Posted by El Pinguino

That works fine if you are hand steering and sitting or standing behind the wheel, other wise - if you are on autopliot - not so useful.

Originally Posted by nofacey

Sorry El Pinguino, but that is so not true - where you are on board (and who or what is steering the ship) is irrelevant, as long as the boat is following a steady course and you yourself are staying stationary.
Line up the vessel in question with any fixed point aboard your boat, and stay still yourself(seated at the stern, or Port amidships or wherever…though this would be tough to do on the bow)…..if the vessel in question moves towards your bow, they’re going to be ahead of you, if they’re falling back, behind……but if they remain lined up on the selected point on your boat…..you’re going to hit.

Originally Posted by El Pinguino

Sigh..... OK you have to be stationary either on the wheel or elsewhere.. no popping below to put the kettle on.

In theory it seems sheer impossible to do, but in reality it is much easier. You take a position that you like to sit in and in the same pose. This is a quickly acquired skill and it allows you to come and go and compare bearings. For the movements of the boat you also quickly learn to take bearing at the same moment of the cycling motion of steering and wave action. This even works better with an autopilot because it reacts exactly the same with each passing wave.

[s/v Jedi]

Originally Posted by Ronny170

Again, this is incorrect. If we are talking about two vessels on collision courses, relative bearing (in theory, practical measurement arguments aside) and compass bearing to target will remain constant, and it will remain steady on EBL etc, etc AND the target vessel will "make trees" at a constant rate as well, as determined by the observing vessel's speed. This really shouldn't even be part of the debate here. What was being discussed is what that forward motion or amount of "tree making" actually looks like when on collision courses, vs not on collision course.

No you are twisting it again. You are making this a slapstick circus. When the EBL is pointing at the tree and the target remains on the EBL, then the target is NOT making trees. You say it IS making trees and being unable to grasp that is the problem only you seem to have… all the rest of us understand it.