Pilotage Done Properly

[AntarcticPilot]

Yes, I was only thinking of the navigation use at comfortable latitudes. It must be considerably less use than a chocolate teapot at the poles!

Fortunately we are blessed with plenty of projections to choose from...

Its mathematical infelicities are global, but unlikely to affect celestial navigation; they only come into force when considering the ellipsoidal case. They are worse for the Transverse form than for the normal aspect. However, I once calculated the scale change across a Mercator planning chart of the North Atlantic - it was around 50%, so NOT insignificant.

 

[mogmog2]

I haven’t read the article, but I got a particular pilot book for Xmas which I have been looking forward to getting. I own many pilot books and cruising guides, so I’m pretty familiar with the format. In this case I was disappointed to find the vast majority of the book is devoted to safety advice, and far less to actual passage planning. The book also assumes you have an 11m yacht and asks you to re-plan accordingly if you don’t. I could have got the info I actually need from the web. If a less experienced sailor picked up this book they would likely give up all ambition of sailing in the area and buy a caravan instead.

Would you please spare me and probably others, the disappointment? - I'm at the stage of acquiring pilot books and don't need a safety book. Thanks.

 

[Mark-1]

I was exhausted just reading it

Your complete guide to yacht pilotage (done properly) - Yachting Monthly

If I was being paid by the word I would defiantly add a long paragraph on 3D models!

Salcombe is really well buoyed, it wouldn't be my first choice example of a a challenging entrance. Before the kids ruined enhanced my life I used to actively seek out challenging pilotage and, for me as a soft South-coaster, challenging pilotage is the remote places in Scotland without man made navaids where you go in on on a transit on 'the tallest of the three mountain tops' or 'the slightly lighter patch of gravel'. But the mountain tops look bloody identical heights and there seem an infinite number of light gravel patches. And the thing you identified as a white rock gets up and flies away. Oh yeah, and some of the charted rocks are apocryphal and when you row over to check one seems to exist and one seems not to.

 

[capnsensible]

One of the basic rules of pilotage is to never use mountain or hill tops. Far too unreliable.

The exception would be if a hill has a distinguishing feature on it like a communications mast or a statue of Jesus.

 

[RunAgroundHard]

One of the basic rules of pilotage is to never use mountain or hill tops. Far too unreliable.

The exception would be if a hill has a distinguishing feature on it like a communications mast or a statue of Jesus.

Interesting perspective as hill or mountain tops are common pilotage targets when steering into places on the WCoS. Of course, the helm and navigator need to be using the same summit.

 

[newtothis]

One of the basic rules of pilotage is to never use mountain or hill tops. Far too unreliable.

The exception would be if a hill has a distinguishing feature on it like a communications mast or a statue of Jesus.

Relying on divine intervention in pilotage will never end well

 

[Mark-1]

One of the basic rules of pilotage is to never use mountain or hill tops. Far too unreliable.

I doubt that, maybe you can provide a source for that rule?

If it is, certainly nobody has ever told the people who write pilot books. Such use is ubiquitous.

Even if you're someone who doesn't like remote anchorages, how about Stoke Clump? That's been part of a transit since before Nelson's time and likely since the Romans.

 

[Roberto]

The exception would be if a hill has a distinguishing feature on it like a communications mast or a statue of Jesus.

Relying on divine intervention in pilotage will never end well

Enter by the Corcovado Jesus by the tower top, then anchor on one side

 

[Mark-1]

Relying on divine intervention in pilotage will never end well

Who do you think put the 'Conspicuous Rock' there in the first place for us to aim at? (Ok, that might have been Slartibartfast rather than the Almighty.)

 

[capnsensible]

I doubt that, maybe you can provide a source for that rule?

If it is, certainly nobody has ever told the people who write pilot books. Such use is ubiquitous.

Even if you're someone who doesn't like remote anchorages, how about Stoke Clump? That's been part of a transit since before Nelson's time and likely since the Romans.

You have to be absolutely sure its unambiguous. That's why mountains and hills are so unreliable. Use left or right hand edges of land., you moaned about it in post #63.

Basic pilotage.

 

[zoidberg]

I guessed you were an XKCD fan, Antarctic... I nearly posted the "what your chosen map projection says about you" comic in this thread already, now I know it belongs!
Map Projections
Not fair on Mercator though....

Wow! XKCD.....

That's the muvver of a rabbit-hole.

"I'm just going inside. I may be some time...."!

 

[capnsensible]

Interesting perspective as hill or mountain tops are common pilotage targets when steering into places on the WCoS. Of course, the helm and navigator need to be using the same summit.

I sailed a lot on the West Coast of Scotland. Plenty of good reasons there not to look up to do boat pilotage. Too much to go wrong. That's probably why there are far more accidents going in or out of harbour than there are at sea. To quote J. Stevens in his Yachtmaster Handbook.

 

[zoidberg]

"The land claims more ships than the sea"

 

[RunAgroundHard]

I sailed a lot on the West Coast of Scotland. Plenty of good reasons there not to look up to do boat pilotage. Too much to go wrong. That's probably why there are far more accidents going in or out of harbour than there are at sea. To quote J. Stevens in his Yachtmaster Handbook.

I would agree if a summit was used in isolation, but good pilotage is not like that, lots of markers are used to pilot the vessel in. Many a time, entering a tricky loch, the command to steer for a summit has been given, as have other helm orders as the case requires, in conjunction with using the pilotage notes, leading lines, depths, buoys et cetera in whatever form has been developed. Whomever is in charge of pilotage, the person on the helm, or a skipper instructing crew to steer, a summit can easily be used with a lower mark to create a transit. Often at night, in a dark loch, the summit may be the clearest thing against the sky, unless a particular star is obvious. We can disagree on the point, but I have never found it an issue. I do agree that everyone staring up at a summit when entering a place is a recipe for disaster, but that should never be the case.

 

[capnsensible]

I would agree if a summit was used in isolation, but good pilotage is not like that, lots of markers are used to pilot the vessel in. Many a time, entering a tricky loch, the command to steer for a summit has been given, as have other helm orders as the case requires, in conjunction with using the pilotage notes, leading lines, depths, buoys et cetera in whatever form has been developed. Whomever is in charge of pilotage, the person on the helm, or a skipper instructing crew to steer, a summit can easily be used with a lower mark to create a transit. Often at night, in a dark loch, the summit may be the clearest thing against the sky, unless a particular star is obvious. We can disagree on the point, but I have never found it an issue. I do agree that everyone staring up at a summit when entering a place is a recipe for disaster, but that should never be the case.

You mention other techniques in pilotage. I trust those, not a summit that may, from sea level, not be a summit. Likewise, I trust those experienced sailors that taught me many tides ago.

 

[Mark-1]

I would agree if a summit was used in isolation, but good pilotage is not like that, lots of markers are used to pilot the vessel in.

I'm not sure I'd even totally agree with that. Clearly lots of helpful features would be nice, but there won't always be lots of features at useful points, nature isn't like that. The authors of pilot books have to work with the features that happen to be in the right place even if they're indistinct and difficult to identify. If the most distinctive feature in the right place is a peak then that's what they had to go with. Helpful people might (say) paint a rock white or build a cairn, obvs.

It's a bit like anchor transits. It would be wonderful to have loads of distinct transits to check, but you have to work with what's there.

Often at night, in a dark loch, the summit may be the clearest thing against the sky, unless a particular star is obvious. We can disagree on the point, but I have never found it an issue.

TBH, I have, which is why I offered it as an example but identifying stuff is part of the fun of pilotage. Not much challenge in going to places with loads of clear man made navaids.

 

[RunAgroundHard]

You mention other techniques in pilotage. I trust those, not a summit that may, from sea level, not be a summit. Likewise, I trust those experienced sailors that taught me many tides ago.

Well, I disagree and in the real world I have found summits very clear aids based on my experience and not others. Also elevated valley lowest points, clumps of trees, dark patches of land and other natural features that stand out and are good enough for short duration use.

 

[Mark-1]

Well, I disagree and in the real world I have found summits very clear aids based on my experience and not others. Also elevated valley lowest points, clumps of trees, dark patches of land and other natural features that stand out and are good enough for short duration use.

Yeah. I'd been a bit suckered into thinking summits were poor but actually they're superb. They never, ever move. They're highly visible. A cairn can be knocked apart, white paint on a rock doesn't last.

I mentioned Stoke Clump, earlier. The man made transit indicators are long gone but Stoke Clump can still be lined up with a post or 33 degrees (I think) as it has for centuries and likely millennia.

I offered them as an example of being difficult to identify but, on reflection, that was a problem with the pilot book. If, instead of tallest, they'd said (say) most eastward it would have been easy. (As it was I worked it out with an OS map pretty quickly which was part of the fun.)

Yeah. Peaks are excellent for pilotage.

 

[capnsensible]

Well, I disagree and in the real world I have found summits very clear aids based on my experience and not others. Also elevated valley lowest points, clumps of trees, dark patches of land and other natural features that stand out and are good enough for short duration use.

Scotland. If you can't see the hills, it's raining. If you can, it's about to rain.

 

[capnsensible]

Yeah. I'd been a bit suckered into thinking summits were poor but actually they're superb. They never, ever move. They're highly visible. A cairn can be knocked apart, white paint on a rock doesn't last.

I mentioned Stoke Clump, earlier. The man made transit indicators are long gone but Stoke Clump can still be lined up with a post or 33 degrees (I think) as it has for centuries and likely millennia.

I offered them as an example of being difficult to identify but, on reflection, that was a problem with the pilot book. If, instead of tallest, they'd said (say) most eastward it would have been easy. (As it was I worked it out with an OS map pretty quickly which was part of the fun.)

Yeah. Peaks are excellent for pilotage.

Be careful. If you attempt to use your one single example in most places in the world, you're gonna have a bad hair day.