Radar or AIS to rouse me when in a stupor?

[chubby]

[QUOTE=JebLostInSpace;3724494]I'm late to the party again, but one consideration I haven't seen much discussion on, but which would influence this decision for me is power consumption. On my boat, I have AIS receive only and radar. (I am actively shopping for AIS transmit, but probably won't buy until I'm gearing up for the next significant passage).

With my radar unit, I would be hard pressed to supply the needed power to run it all the time. I'm just about power neutral on sunny days, and run the generator for a bit in the evening to make dinner on my awful electric galley that I hate... but I digress. Then the batteries are full heading into overnight, and can run the autopilot, plotter, instruments, AIS receive, and nav lights all night. If I add the radar to that load, I am likely running the genset again before sunrise, which sucks.

Maybe if you're singlehanding (I don't singlehand overnight), it sucks a little less to run the genset cause you're up anyway. Or maybe you have enough battery bank that this doesn't matter for you. Or maybe the newer units just don't use much power. But for me, running the radar makes my power management obnoxious, so I don't tend to use it overnight unless there is some adverse condition. If I do feel the need to turn it on, I usually turn it on for a few minutes, then cycle it off again to conserve power. You wouldn't have that option if you are wanting to run the radar while you nap.[/QUOTE]



what you described is what Furuno calls their "watchman" mode or Garmin calls their "Timed Transmit" Mode...(not familiar with others but i assume they have the same functions)


the radar basically sits in low power standby for whatever interval you decide..
..then transmits and then compares to previous scans.
any changes --> you need to take a look. very simple..


...the power saving is significant without compromising you keeping your situation awareness (even when captain is tired or in a stupor)

[mcon12000]

I single hand, multi day passages.

Radar is essential but to anyone reading this the older units will drive you crazy with false alarms. The newer units like the OP is now considering are much better. To the person saying “learn how to adjust your radar settings” there’s little you can do in rough seas while still picking up a 50’ object.

An AIS Transponder is just as important in my opinion so commercial traffic are aware of you and your intentions. If you’re broadcasting they’ll be able to avoid you if you fail to respond. I’m not a fan of receive only as only one vessel is aware of potential danger and that boats captain might be napping.

Anyway this is just part of the equation (big one) but I do other things like slowing down at night. I figure if I hit a semi submerged object in the darkness the slower the better. That’s just me, near shore and the further from land I get the less I worry about debris. Actually I always worry just less.

[donradcliffe]

I am not saying that radar isn't useful, but I seriously doubt whether those recommending it before AIS for rousing a singlehander have ever used the alarm system at sea. It all seems so simple in the brochure, but the reality is something else.

First, you have wave returns that are more frequent and stronger the closer they are to your boat. They will set off a spurious alarm. You can use the sea state controls to reduce the gain near the boat, but then you lose the ability to see targets within a mile or two. The real small boat targets are those that give a faint echo close in, and the only way to distinguish them from wave returns is to watch for several revolutions and see if they pop up in the same spot--all while you are supposedly sleeping.

The best guard zone is a doughnut which alarms when a target moves into a zone between 2 and 6 miles from you. But wait, are you going down the coast? Then you have to suppress the targets on the land side, ending up with half a doughnut.

After all this, half the targets are probably moving away from you.

Then there is rain.

Then there is the fact that the built in alarms are not loud enough to wake you when you are exhausted. Both radar and AIS systems need a powerful external alarm.

[nofacey]

You need to learn to use radar - the pretty ads don’t mention how sensitive it is to atmospheric/wave conditions, and the need to get it right for that night, or suffer frequent nuisance alarms. I agree it should come first.

On a comparative basis, AIS is plug n play, & far more consistent. There will still be issues with excessive alarming in busy areas.

[smj]

Originally Posted by mcon12000

I single hand, multi day passages.



Radar is essential but to anyone reading this the older units will drive you crazy with false alarms. The newer units like the OP is now considering are much better. To the person saying “learn how to adjust your radar settings” there’s little you can do in rough seas while still picking up a 50’ object.



An AIS Transponder is just as important in my opinion so commercial traffic are aware of you and your intentions. If you’re broadcasting they’ll be able to avoid you if you fail to respond. I’m not a fan of receive only as only one vessel is aware of potential danger and that boats captain might be napping.



Anyway this is just part of the equation (big one) but I do other things like slowing down at night. I figure if I hit a semi submerged object in the darkness the slower the better. That’s just me, near shore and the further from land I get the less I worry about debris. Actually I always worry just less.

Do you rely on commercial traffic seeing you or is it a possibility they have filtered out the small boat traffic?
Can’t blame them for filtering out small boat traffic while coastal with all the people that insist on transmitting while either at the dock, on anchor or on a mooring.

[wholybee]

Originally Posted by donradcliffe

I am not saying that radar isn't useful, but I seriously doubt whether those recommending it before AIS for rousing a singlehander have ever used the alarm system at sea. It all seems so simple in the brochure, but the reality is something else.

First, you have wave returns that are more frequent and stronger the closer they are to your boat. They will set off a spurious alarm. You can use the sea state controls to reduce the gain near the boat, but then you lose the ability to see targets within a mile or two. The real small boat targets are those that give a faint echo close in, and the only way to distinguish them from wave returns is to watch for several revolutions and see if they pop up in the same spot--all while you are supposedly sleeping.

The best guard zone is a doughnut which alarms when a target moves into a zone between 2 and 6 miles from you. But wait, are you going down the coast? Then you have to suppress the targets on the land side, ending up with half a doughnut.

After all this, half the targets are probably moving away from you.

Then there is rain.

Then there is the fact that the built in alarms are not loud enough to wake you when you are exhausted. Both radar and AIS systems need a powerful external alarm.

I use the AIS alarm on my VHF radio. Lots of complaints with how the AIS interface works on a VHF, but the alarm is loud.

[mcon12000]

Originally Posted by smj

Do you rely on commercial traffic seeing you or is it a possibility they have filtered out the small boat traffic?
Can’t blame them for filtering out small boat traffic while coastal with all the people that insist on transmitting while either at the dock, on anchor or on a mooring.

I do not assume anything but I’m not sure of your point? If you where incapacitated others could avoid you but this would be a last resort not a standard way of operating. Certainly can’t be relied on to be 100% effective.

AIS isn’t a substitute for situational awareness or radar but that’s just my opinion.

Are you a commercial captain? Only asking so that you might give the readers that perspective. Most of the commercial guys I’ve spoken to prefer that recreational vessels broadcast.

[smj]

Originally Posted by mcon12000

I do not assume anything but I’m not sure of your point? If you where incapacitated others could avoid you but this would be a last resort not a standard way of operating. Certainly can’t be relied on to be 100% effective.



AIS isn’t a substitute for situational awareness or radar but that’s just my opinion.



Are you a commercial captain? Only asking so that you might give the readers that perspective. Most of the commercial guys I’ve spoken to prefer that recreational vessels broadcast.

Commercial captain? No, but I’ve heard there are some frustrated commercial captains out there dealing with a screen full of AIS targets.
I absolutely agree, both radar and AIS come in a very distant second to old fashioned eyeball navigation, but others consider it an absolute necessity.
My main beef is those that use AIS as a find your friend in an anchorage app. It was meant as a navigational tool?

[wholybee]

Originally Posted by smj

Commercial captain? No, but I’ve heard there are some frustrated commercial captains out there dealing with a screen full of AIS targets.
I absolutely agree, both radar and AIS come in a very distant second to old fashioned eyeball navigation, but others consider it an absolute necessity.
My main beef is those that use AIS as a find your friend in an anchorage app. It was meant as a navigational tool?

Don't chart plotters have the ability to hide targets that are not "important?" Displaying everything withing about a half mile(configurable), and outside of that only show class B if there is a close CPA? A chart plotter display shouldn't be that cluttered, unless there are a hundred ships all on a collision course.

Isn't "finding a friend" a navigational use? I can't count how many times I or a friend of mine has done this. Not just within an anchorage, but what anchorage, if one boat in a group arrives a day earlier. Or, in a crowded port with several marinas, to help navigating to the correct one. Would you rather we/they clog the VHF with "Where are you? I don't see you?" calls?

[smj]

Originally Posted by wholybee

Don't chart plotters have the ability to hide targets that are not "important?" Displaying everything withing about a half mile(configurable), and outside of that only show class B if there is a close CPA? A chart plotter display shouldn't be that cluttered, unless there are a hundred ships all on a collision course.



Isn't "finding a friend" a navigational use? I can't count how many times I or a friend of mine has done this. Not just within an anchorage, but what anchorage, if one boat in a group arrives a day earlier. Or, in a crowded port with several marinas, to help navigating to the correct one. Would you rather we/they clog the VHF with "Where are you? I don't see you?" calls?

So if the commercial traffic hides you as your not important then they are unaware your there and unaware of your intentions?
I think AIS was developed with safety in mind, not a way to find your friend in an anchorage. But yes, a friendly call on the vhf would be perfectly fine.
Maybe a “social” form of AIS could be produced that would run on a separate frequency and wouldn’t show up or clutter the AIS navigational aid? That may be a welcome addition.

[wholybee]

Originally Posted by smj

So if the commercial traffic hides you as your not important then they are unaware your there and unaware of your intentions?
I think AIS was developed with safety in mind, not a way to find your friend in an anchorage. But yes, a friendly call on the vhf would be perfectly fine.
Maybe a “social” form of AIS could be produced that would run on a separate frequency and wouldn’t show up or clutter the AIS navigational aid? That may be a welcome addition.

Not important targets would be those that based on AIS data will not have a close CPA. So, it really doesn't matter to a commercial ship what your intentions are, because they don't affect them. If you change course and CPA gets close, then you pop up on their screen. Also, usually nothing is hidden unless there are some large numbers of targets displayed, like 50 or 100. Commercial traffic would not be losing any useful information by hiding unimportant targets.

Social AIS? So by participating in this I am now invisible to those with regular AIS? How dumb is that? Someone looking at AIS to find friend isn't a problem. It doesn't affect you, commercial traffic, or anyone. It is between those 2 boats. Why do you care? OTOH, excessive VHF traffic in crowded areas IS a problem.

It sounds like you are arguing that small boats just shouldn't have AIS at all. Which is an incredibly bad idea. I just don't understand your objection.

[Montanan]

Come now Chotu, since when did a post of yours ever go off the rails?

I would prefer Radar over AIS for the reasons stated in the above posts, but advocate for both.

Bon voyages.

[smj]

Originally Posted by wholybee

Not important targets would be those that based on AIS data will not have a close CPA. So, it really doesn't matter to a commercial ship what your intentions are, because they don't affect them. If you change course and CPA gets close, then you pop up on their screen. Also, usually nothing is hidden unless there are some large numbers of targets displayed, like 50 or 100. Commercial traffic would not be losing any useful information by hiding unimportant targets.



Social AIS? So by participating in this I am now invisible to those with regular AIS? How dumb is that? Someone looking at AIS to find friend isn't a problem. It doesn't affect you, commercial traffic, or anyone. It is between those 2 boats. Why do you care? OTOH, excessive VHF traffic in crowded areas IS a problem.



It sounds like you are arguing that small boats just shouldn't have AIS at all. Which is an incredibly bad idea. I just don't understand your objection.

I sincerely hope you find your friends.

[Jim Cate]

Originally Posted by Happ

To me Radar is most important. First in gives you a significant range to most everything like weather, headlands, possibly objects in the water and boats without AIS or do not have transceivers. Without a transceiver they are not receiving you because they are only transmitting which means its on you to avoid. I would ad AIS as it is a way to alert others of your presence. Both systems can be set with alarms so there is a good chance of some redundancy. B

Curious where are you sailing? Crossings or coastal waters. As another option if you are sailing coastal you can always pull in and take a break when you’re getting tired. Better to take a few extra days then have a problem.

As a side note going down below for 5 or 10 minutes should never be a problem as you can lookout and see any possible issues that might occur before you take a break.

You might want to review how AIS works. Non transponders receive only and don't transmit, not what you have stated above.

Jim

[SV Confianza]

Chotu, if you have a fast boat, you might not need to do an overnight at all, if you plan your weather right. The only jump that requires an overnight is Virginia Beach to Morehead City (around Hatteras), unless you can average like 12 kts.

We just hopped down from Maine to Florida, and Hatteras was the only overnight we required. And we only average 7-8kts.

Without beating everything else to death here, I have to put a huge vote in for just saving on other things and getting both. It's safety and loss of life we're talking.

Set the Axiom to chart mode and overlay both radar and AIS. We have the Axiom and the quantum radar. The radar alarms are tricky to get right (impossible if you're too close to land). Setting the guard zones to a thinner circle helps. But it will still go off when you don't want it to.

95% of boats offshore at night on east coast will have AIS, and will actively stay away from you because they know your position and heading via AIS. There are some fishing boats that are not on AIS, usually within 5ish miles of land, but also usually lit up light a Christmas tree while fishing at night.

With the overlays set up, you easily identify a blip on radar that's NOT on AIS, and can keep track of.

It's SO worth it to have both...

We used to offshore sail without either, and I couldn't even imagine going back.

I know boats just eat money, but my humble opinion is that the navigation equipment is worth prioritizing.