Radar Reflectors -- observations and musings

[LakeSuperior]

Originally Posted by CaptTom

What's all this talk about substitutes?

Use every source of data you've got. The Polynesians sailed the Pacific using (among many other things) the direction of swells reflected off islands.

You should never "substitute" anything. Nor should you dismiss any source of data simply because it's not perfect.

I've never read any accounts about what happened when they misread the reflected wave trains in the vastness of the Pacific.

[deblen]

Originally Posted by dlj

Key word is should. I have been rather surprised at how some of the big freighters do not run AIS.

Depending upon where, a lot of fishing boats do not use AIS. I just sailed up the coast of Nova Scotia and Newfoundland and found many of the fishing boats here so use AiS, but certainly not all.

Until close to 100% of all boats in the world use AIS, RADAR will remain very useful for spotting boats. Additionally, RADAR will still be very useful in areas with fog or other low visibility.

Running with both is highly desirable for long distance cruising, in my opinion.

dj

For US vessels: https://www.navcen.uscg.gov/sites/de...s/navrules.pdf

[deblen]

Originally Posted by dlj

Question: who must comply with SOLAS? How is it enforced? It's also my understanding fishing boats are exempt.

My statement comes from direct observation.

dj

US vessels: https://www.navcen.uscg.gov/sites/de...s/navrules.pdf

[dlj]

Originally Posted by deblen

US vessels: https://www.navcen.uscg.gov/sites/de...s/navrules.pdf

Pretty limited number of large freighters/tankers/cargo ships are registered in the US. Many non-US flagged boat are carrying AIS but a surprising number are not.

So I personally don't think RADAR is ever going the way of the SSB. At least iny lifetime.

dj

[deblen]

Originally Posted by dlj

Pretty limited number of large freighters/tankers/cargo ships are registered in the US. Many non-US flagged boat are carrying AIS but a surprising number are not.

So I personally don't think RADAR is ever going the way of the SSB. At least iny lifetime.

dj

I fully agreeFog.jpg Views: 34 Size: 73.3 KB ID: 280890" style="margin: 2px" />

[hjohnson]

Originally Posted by dlj

Pretty limited number of large freighters/tankers/cargo ships are registered in the US. Many non-US flagged boat are carrying AIS but a surprising number are not.

So I personally don't think RADAR is ever going the way of the SSB. At least iny lifetime.

dj

In 10 years of navigating in/out of Vancouver harbour, I have yet to see a commercial deep sea that wasn’t running AIS. Warships? Sometimes no, though RCN usually has it on, and I know most/all are receiving as part of situational awareness. Fishing boats? Yeah, a lot don’t have them, as do virtually all the tugs operating in the area.

Now it’s not a replacement for radar, never said it was. However, every indication I’ve had is that my rig shows up well enough on X-band radars, that I’m comfortable with that + AIS. If we were out in truly foul weather, yeah I would probably hang it up, but for the most part I’m a fair weather boy.

[CaptTom]

Originally Posted by LakeSuperior

I've never read any accounts about what happened when they misread the reflected wave trains in the vastness of the Pacific.

No doubt some of them didn't succeed. But that's true with any technology. I'd put their skills against anyone on this forum.

I've talked with the navigator who brought one of their Ocean going canoes to Nova Scotia. I have a lot of faith in his abilities. But even he had the good sense to enlist a chase boat with full electronics, in the unfamiliar waters of the North Atlantic. You don't dismiss a new technology just because you're good at using what you already have.

[dlj]

Originally Posted by hjohnson

In 10 years of navigating in/out of Vancouver harbour, I have yet to see a commercial deep sea that wasn’t running AIS.

Coming up the coast of Newfoundland this August, I was running in fog with both AIS and Radar and a very large RADAR hit running only a fog horn traveling at about 12 knots passed me on my port side about 2 NM away. All indications - except not running AIS - indicated that was a freighter. Although as I think about it, I couldn't prove that. Everything about that said "freighter" to me but as I now think about it - not sure what else it would have been - but I guess I actually don't know.

dj

[Jammer]

Originally Posted by LakeSuperior

I've never read any accounts about what happened when they misread the reflected wave trains in the vastness of the Pacific.

There's a fascinating book titled "Barefoot Navigation" that explores the navigational traditions there and some of what we might call "celestial light" that they used. Running down latitudes, looking for a zenith star for a particular latitude/island, using certain "star trains" that provide a series of heading references on the horizon. Directions between islands embedded in poems.


So, not a single technique, but a rich tradition that melded a variety of methods.

[Jim Cate]

Originally Posted by Jammer

There's a fascinating book titled "Barefoot Navigation" that explores the navigational traditions there and some of what we might call "celestial light" that they used. Running down latitudes, looking for a zenith star for a particular latitude/island, using certain "star trains" that provide a series of heading references on the horizon. Directions between islands embedded in poems.


So, not a single technique, but a rich tradition that melded a variety of methods.

They were clever navigators for sure, but I don't think we have any idea of how many voyagers disappeared forever vs those who safely arrived at their destinations (or ANY destination).

Jim

[deblen]

The Vikings navigated:

https://www.youtube.com/watch?v=YzDvSY7xf9I

[CaptTom]

Amazing stuff! I'm in awe at how the ancient navigators like the Vikings did it.

I'll just add that their descendants still navigate the world's oceans... but they use AIS. A skilled navigator will use whatever information they can get. Not cling to old ways just because it worked for them before.

[Dockhead]

Originally Posted by CaptTom

Amazing stuff! I'm in awe at how the ancient navigators like the Vikings did it.

I'll just add that their descendants still navigate the world's oceans... but they use AIS. A skilled navigator will use whatever information they can get. Not cling to old ways just because it worked for them before.

Absolutely right! Wise words