AIS, Radar or both?

[sharkwatcher]

Originally Posted by Stu Jackson

I can't tell whether you meant this in a nice way or are just rude. Most of the AIS vs Radar posts are within the past year when technology hasn't much changed. And the concepts haven't changed at all since transceivers became available for recreational boats, since radar for rec boats has been around for a long time. This is NOT a timeliness issue at all.

You also might want to investigate your avatar, which says you have a very short sailboat.

It may be shorter that a lot of boats, but 31' is not "short"!

[s/v Moondancer]

After 8 years and 30,000+nm between Nova Scotia, the Caribbean and crossing the Pacific
with both radar and an AIS transceiver...The answer is BOTH but AIS has been more valuable from Miami south.

We run our AIS off a VHF splitter off the masthead antenna and it gives us a 22 nm range on AIS.

A year ago we were under emergency tiller for 90nm in the approaches to the Panama Canal. The AIS allowed us to contact dozens of ships, by name, and request a 1nm+ safe passage. A transceiver is far more valuable than a receiver as it allows big ships to 'see' you and more easily provide a safe passage.

Radar is important for fog and vessels not transmitting AIS information but AIS is a real game-changer!

[a64pilot]

Originally Posted by sharkwatcher

It may be shorter that a lot of boats, but 31' is not "short"!

Your right it's not, but your signature says you have a 31 INCH boat, which would be pretty short.
I am certain it was meant as a nice tease, no offense meant.

[sharkwatcher]

Originally Posted by a64pilot

Your right it's not, but your signature says you have a 31 INCH boat, which would be pretty short.
I am certain it was meant as a nice tease, no offense meant.

Thanks, I never picked upon the typo, correcting it now, LOL!

[sharkwatcher]

My intent with my remarks about going thru past post was not intended to be rude. I have read thru most of those post before I posted. I do get a bit annoyed by the "Why are you asking, go use the search" reply that some people on forums use, rather than asking If that was tried first. I always use the search first and only resort to posting a question when what I'm looking is either clearification or current wisdom. I'm asking for help from others I assume are more experienced on the topic and are on the forum to spread that knowledge.

[Dockhead]

Originally Posted by a64pilot

Anyone know of a pattern I can get and cut out a reflector?
Its a simple thing, ought to be easy and I would think maybe even be made so it could be taken apart and stowed flat?

An issue is I think a simple corner reflector would need to be maybe 2' in diameter to be very effective.

Im sure you can make it yourself, but it will have less windage, look better, and snag fewer lines if you buy one. Thats what I would do.

[a64pilot]

Our search leaves a little to be desired, use the Google Custom Search and it will work a lot better

[a64pilot]

Originally Posted by Dockhead

Im sure you can make it yourself, but it will have less windage, look better, and snag fewer lines if you buy one. Thats what I would do.

If I can get a pattern I can get engineering to put in in AutoCad and have the laser cut it out of aluminum sheet here at work, plus I can make it any size I want. Can only make one though as I don't own the place
From my previous life I know a little about Radar theory and operation, and if you go up in size from a 12" corner reflector to say a 24" one, your RCS is much larger, way larger, I don't know how much, but way more than twice.

[Dockhead]

Originally Posted by a64pilot

If I can get a pattern I can get engineering to put in in AutoCad and have the laser cut it out of aluminum sheet here at work, plus I can make it any size I want. Can only make one though as I don't own the place
From my previous life I know a little about Radar theory and operation, and if you go up in size from a 12" corner reflector to say a 24" one, your RCS is much larger, way larger, I don't know how much, but way more than twice.

OK, then.

What gou say about size jives with what I remember from the PBO article - IIRC, the skinny ones were useless. Probably need to be a certain proportion of the wavelength used, for it to work well, Im guessing.

[Terra Nova]

Originally Posted by a64pilot

...if you go up in size from a 12" corner reflector to say a 24" one, your RCS is much larger...

Your windage goes up exponentially.

[a64pilot]

Originally Posted by Terra Nova

Your windage goes up exponentially.

I wouldn't be surprised if it doesn't at the same rate the RCS does.
But I plan on leaving it dis-assembled til I need it, and at least around here, decent sailing wind and heavy fog together, are very rare occurrences.
Just night sailing in good vis, I don't worry so much, between AIS and Radar and the ole Mark 1 eye ball I think I'm OK.
I may just give up and go with the 12.5" Davis I find for sale.

[Stu Jackson]

Originally Posted by sharkwatcher

My intent with my remarks about going thru past post was not intended to be rude. I have read thru most of those post before I posted. I do get a bit annoyed by the "Why are you asking, go use the search" reply that some people on forums use, rather than asking If that was tried first. I always use the search first and only resort to posting a question when what I'm looking is either clearification or current wisdom. I'm asking for help from others I assume are more experienced on the topic and are on the forum to spread that knowledge.

Thanks for that clarification, which is why I said what I did and how I did it. We simply can't read minds, so we didn't know you'd done that research & homework, and a64 is right, the Google custom search is much better.

Thanks again, and good luck, hope we've helped.

[SailFastTri]

Both -- It's like asking "hearing, seeing or both"?

[mcarling]

My opinion is that have an AIS transmitter reduces the need for a radar reflector but an AIS receiver doesn't much reduce the need for radar itself. If I had to choose between AIS and radar ceteris paribus, I would choose radar. However, AIS is much less expensive and generally easier to install, so if price were a major constraint then AIS might be the better option. If funds permit, definitely get both AIS and radar. As several other posters have already observed, AIS and radar solve different problems. They are not very fungible. The legal requirement to keep watch can be met with radar, but not with AIS.

[Paul L]

You didn't mention where you plan to cruise. It makes a difference. If you are doing extensive cruising in mid lower latitudes I would select an AIS transceicver first. Most other vessels will see you offshore and many inshore will see you. You will see almost all large vessels will in advance and have their names readily available. All for a reasonable investment.
If you have additional money to spend then I'd consider adding radar. Radar would be higher on my list if you plan to cruise in areas with fog. I really like having a modern radar onboard, but the reality is we don't use it that much. Main uses are to look at distant squals to determine their direction and density, and to track vessels without ais that we can't determine their course visually.