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AIS/VHF/Plotter question

Marlin Prowell

E34 - Bellingham, WA
Both the VHF and the Vesper WatchMate need a second 12v power connection. The NMEA2000 bus can provide a small amount of current to devices on the bus, but your two devices need much more current than the NMEA2000 bus can provide, so a second power connection is required.

You should not solder any terminal connector wires. Solder creates a rigid connection between the wire and the connector and the connection can fail with the constant vibration on a boat.

I use heat shrink ring terminals for all my connections. The heat shrink tubing seals the connection between the terminal and the wire, preventing corrosion, and also provides some extra strength where the wire meets the connector. I have replaced several non heat shrink terminal connectors that were installed when the boat was built and had corroded over time.
 

bgary

Advanced Beginner
Blogs Author
- I am planning to connect the AIS to the VHF... even though the VHF has an AIS receievr and internal GPS... unless that is crazy talk. My main reason is I figured the external GPS antenna on the Vesper would be better than the built-in in the VHF... but maybe these systems should be kept separate for redundancy?

Would probably work, but perhaps unecesssary.

Vesper makes a smart antenna splitter - plug both the AIS transponder and the VHF into it, and magic happens - the AIS uses the masthead antenna for its outbound signal, and whenever you key the mike it switches over to send your VHF signal. So, best of both worlds. Especially if coupled with the Vesper antenna

As a bonus, it has a third connector for your stereo, so FM radio comes in through the masthead, too.


$.02
 

dhill

Member III
I use Ancor tinned copper wires, loop connectors with adhesive, and crimpers to secure my wires. Ancor stuff is expensive, but high quality and I feel that having crimpers that match the brand of the connectors is an additional benefit. Electrics is a detail-oriented business. I use a Ryobi heat gun to shrink the connector tubing onto the wire after crimping and the additional adhesive built into the connector tubing helps ensure a nice water-tight seal that you can see.

I've been looking at AIS systems as well. I like the anchor watch feature of the Vesper products and that will likely tip the scales in their favor. The Cortex system looks great for remote monitoring, but is pricey and I do like to keep things simple, particularly in a harsh marine environment. I have older Raymarine electronics, but they are capable of showing AIS targets with the appropriate NMEA 2000 wiring.
 

windblown

Member III
Would probably work, but perhaps unecesssary.

Vesper makes a smart antenna splitter - plug both the AIS transponder and the VHF into it, and magic happens - the AIS uses the masthead antenna for its outbound signal, and whenever you key the mike it switches over to send your VHF signal. So, best of both worlds. Especially if coupled with the Vesper antenna

As a bonus, it has a third connector for your stereo, so FM radio comes in through the masthead, too.


$.02
Installed this antenna splitter when I added the NMEA network and the Vesper AIS. I also replaced my masthead antenna with the Vesper unit. I’ve been very pleased with this solution. I have the NMEA network on one breaker (the “old” Instruments switch on the panel) and the Vesper/ AIS Splitter on a different breaker. Both my Horizon VHF and Zeus3 MFD are set to get GPS from the Vesper. There are two minor inconveniences with this set up: 1. if the VHF is powered on without/before the splitter, it emits an error alarm, and 2. flipping the breakers in a preferred order seems to be overwhelming for some crew.
 
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N.A.

E34 / SF Bay
Thanks folks!

I'll go with what MarineHowTo (the link Christian posted -- I like that guy. Need to contribute again; sure he can use it after his unfortunate stroke) suggested. I got the fancy crimpers, but need to go down to the boat and see if I have small enough dies... if not, I'll pick up that dsub set. And yes, @dhill , thanks -- ancor with the sealing/glue shrink it what I'll use if I can find small enough ones. Else I'll due the "two-sided" shrink MarineHowTo suggests. PS: @Christian Williams : thanks for the image of your terminal block; that makes it more obvious what people are doing.

@Marlin Prowell -- many thanks; had not been sure if I needed/even should make the 2nd power connection.

I think I may have been confusing in my initial post: I have the powered splitter, which seems like a great idea -- the VHF and AIS/Vesper will share the masthead antenna for longer line-of-sight. It's the GPS antenna I was unsure I needed to also feed to the radio. I am thinking I may try to keep them separate initially, so I have a redundant system, though I'll break out the connections to a terminal block so life isn't hard whenever I want to make a change. I am not replacing the masthead antenna (yet), since I don't want to go up there, and having anyone else do it is expensive.

Planning to put the splitter and VHF on the same breaker -- that way in an emergency the VHF will work, whether or not people remember the power-up sequence. AIS I may leave on a separate breaker, so it's easy to "go dark" if I want, though given where I sail I'm not sure when I'd ever need to do that.

PS: should I be @<name> ' ing people? Or is that not normal etiquette? I am not sure I am doing this right.
 

Christian Williams

E381 - Los Angeles
Senior Moderator
Blogs Author
should I be @<name> ' ing people?

For context, I have no idea whatever what @christianwilliams might mean, signify, or threaten. When I click on it, as in your post, I am carried to my own apparent identity, which appears to me to be on the surface, at least, a tautology, and therefore not very helpful. I am sure there is a rational explanation of @somebody, which I hope to have soon explained to me. Twitter perhaps? Instagram?

Shall I look at my inner arm and find it tattooed there? Now I am afraid to look. What if it is there, and I am not actually here, but "at christianwilliams?"

I don't know the answer to whether we should all be referred to by @, or should campaign against it, or whether it is one of those rare things nowadays, an option, in which those who do and those who don't continue to coexist without rancor.

As the fly said from his leaf, at the conclusion of his eponymous movie, "The Fly," screenplay by @JamesClavell, a former POW who well into the 70s still carried a can of sardines in his pocket so as not to go unexpectedly hungry, "help me!"
 

peaman

Sustaining Member
@Marlin Prowell -- many thanks; had not been sure if I needed/even should make the 2nd power connection.
The installation manuals will tell you when a separate power supply is needed, as it is in most cases. The power feed in the NMEA 2000 network is only for communication between devices, and little else. It won't power any user-end devices other than very simple displays like B&G Triton.

It's the GPS antenna I was unsure I needed to also feed to the radio. I am thinking I may try to keep them separate initially,
If you have the Vesper unit that I think you have (from your earlier posts), it will include a dedicated GPS antenna which can be mounted on the stern rail, or where ever is convenient. The manual makes clear that that antenna must be used, and dedicated only to the Vesper. Additionally, I believe that the VHF you have selected includes its own internal GPS antenna. My VHF is at the nav station and has no trouble getting a good GPS signal.

Planning to put the splitter and VHF on the same breaker -- that way in an emergency the VHF will work, whether or not people remember the power-up sequence. AIS I may leave on a separate breaker, so it's easy to "go dark" if I want, though given where I sail I'm not sure when I'd ever need to do that.
This is the way. No need for a separate breaker for the AIS, since those tend to be limited. Instead, you can install a separate switch (as I did), and you can source such a switch from Vesper.
 

dhill

Member III
PS: should I be @<name> ' ing people? Or is that not normal etiquette? I am not sure I am doing this right.
The advantage of @<name>ing people is that it notifies them that they have been mentioned in a post, which I find useful and can spur further interaction and conversation.
 

bgary

Advanced Beginner
Blogs Author
Planning to put the splitter and VHF on the same breaker -- that way in an emergency the VHF will work, whether or not people remember the power-up sequence. AIS I may leave on a separate breaker, so it's easy to "go dark" if I want, though given where I sail I'm not sure when I'd ever need to do that.

I thought through the same things, and ended up in the opposite spot.

I put the AIS and the splitter on the same breaker, figuring that any time the AIS was active I wanted the splitter active too. And I put the VHF on its own circuit figuring that if, for some reason, the AIS circuit had a problem, it wouldn't affect the VHF (with its separate GPS). The Vesper splitter allows VHF traffic through whether the splitter powered on or not, so no downside as far as I could tell.
 

Pete the Cat

Member III
Huge variables.

I can contribute merely this: I like my Vesper AIS screen at the nav station, next to the VHF radio. I don't even have the AIS function slaved to the chartplotter at the helm, because I would rather contemplate AIS data in the shade and relative quiet down below. And AIS targets clutter up a smallish chartplotter at the helm.

Personally, I 'd never turn this project over to a professional for advice/installation. It gets ridiculously complicated fast, and if you plan and install yourself you know how it works, and can keep it simple. We need very few of the available bells and whistles, and what we do need varies with the sort of sailing we do or aspire to. KISS ought to be a mandatory tattoo for most of us.
I agree with Christian about not turning this over to a "professional". Like many jobs on a boat, you need to know and understand how it is put together and this is not rocket science beyond a boat owner. Also, it seems to me, it is getting harder to find folks who are competent in electrical matters. I also agree with the idea that you need to see your navigation gear without AIS inputs at times because of the clutter. I will probably get some feedback for this, but I really do not see the point in broadcasting AIS out on small boats--the clutter it causes in busy areas seems to add useless complication to navigation--particularly at night. And it seems it could lead to a false sense of security by small vessels---the big guys in shipping lanes probably can't avoid you, even if they wanted to because of their relative speed, maneuverability, and the erratic courses of most small boats under sail. I want to know where the big guys are pouring out 22 kts, not a 27 ft sailboat doing 4 kts on an erratic course. I have noted that that evolution of AIS has improved the response rate of the big guys when you call them, but it seems this is technology that has a downside we should understand and respect.
 

Kalia

1987 Ericson 34-2
I agree with Christian about not turning this over to a "professional". Like many jobs on a boat, you need to know and understand how it is put together and this is not rocket science beyond a boat owner. Also, it seems to me, it is getting harder to find folks who are competent in electrical matters. I also agree with the idea that you need to see your navigation gear without AIS inputs at times because of the clutter. I will probably get some feedback for this, but I really do not see the point in broadcasting AIS out on small boats--the clutter it causes in busy areas seems to add useless complication to navigation--particularly at night. And it seems it could lead to a false sense of security by small vessels---the big guys in shipping lanes probably can't avoid you, even if they wanted to because of their relative speed, maneuverability, and the erratic courses of most small boats under sail. I want to know where the big guys are pouring out 22 kts, not a 27 ft sailboat doing 4 kts on an erratic course. I have noted that that evolution of AIS has improved the response rate of the big guys when you call them, but it seems this is technology that has a downside we should understand and respect.
On busy San Francisco Bay, I consider AIS for a small recreational vessel to be an always on essential safety feature. Case in point: crossing the shipping channel between Angel Island and Richmond in dense fog (as in, no visibility beyond the bow of your boat), the ability to announce your position in real time to commercial vessels is critical. Knowing the position of the hydro jet SF ferry travelling at 30 knots in those conditions is the difference between making your passage or staying at the dock. Watching a tug on the stern of an oil tanker emerge from a fog bank without a warning from your AIS is jarring to say the least. AIS needs no interpretive skills like radar (is it a wave? is it a rain downpour? is it a solid object not reflecting the radar signal?) Even in relatively narrow shipping channels, commercial vessels will divert if necessary rather than hit a slow moving AIS target. Absent an ability to change course, it will be the opportunity to initiate a VHF conversation to avoid a potentially dangerous encounter.
 

Christian Williams

E381 - Los Angeles
Senior Moderator
Blogs Author
The transponder lets them see us--with value unknown in every case, and mostly psychological in my experience.

As you say, the real value of AIS is our own target identification and avoidance, especially CPA and Time to CPA. I studied for years the eyeball judgement of ship intersections, and the dawn of AIS immediately punctured my balloon.

"At night, ship appears at 10-12 miles as single dim white light, easily mistaken for star rising on horizon. Multiple lights appear at 8 miles, indistinct cluster. Color (of running lights) first appears at six miles. Carnival lights at 3-5 nm (most ships have many deck lights and look like a moving used-car lot). Ship engines audible at less that 2 nm, loud at less than 1 nm."

Boy is it better to have AIS.
 

Pete the Cat

Member III
On busy San Francisco Bay, I consider AIS for a small recreational vessel to be an always on essential safety feature. Case in point: crossing the shipping channel between Angel Island and Richmond in dense fog (as in, no visibility beyond the bow of your boat), the ability to announce your position in real time to commercial vessels is critical. Knowing the position of the hydro jet SF ferry travelling at 30 knots in those conditions is the difference between making your passage or staying at the dock. Watching a tug on the stern of an oil tanker emerge from a fog bank without a warning from your AIS is jarring to say the least. AIS needs no interpretive skills like radar (is it a wave? is it a rain downpour? is it a solid object not reflecting the radar signal?) Even in relatively narrow shipping channels, commercial vessels will divert if necessary rather than hit a slow moving AIS target. Absent an ability to change course, it will be the opportunity to initiate a VHF conversation to avoid a potentially dangerous encounter.
I have lived in the Bay Area and sailed on SF Bay for 45 years. Your statement demonstrates my concern about folks placing unwarranted trust in AIS. As you note, fog on SF Bay can come up quickly and envelope your boat in a matter minutes. However, many recreational boats do not have AIS capability and the 20T USCG navigation buoys (that are not always exactly where they are charted) do not broadcast an AIS signal. So trusting your boat and your life to AIS displays in the fog is, IMHO, very dangerous. The ships and ferries have the right of way in all the narrow channels on the Bay and while they will do their best to avoid you when they are elsewhere, they frequently have a very limited ability to do so. AIS is one source of helpful information, but it is only one. And one that should not be relied upon for vessel separation in dense fog. I fear too many folks are not developing their skills with radar and general watch keeping because they are relying on AIS and chartplotter technology instead of taking personal responsibility to use all means to see and be seen in poor visibility situations.
 

Kalia

1987 Ericson 34-2
I have lived in the Bay Area and sailed on SF Bay for 45 years. Your statement demonstrates my concern about folks placing unwarranted trust in AIS. As you note, fog on SF Bay can come up quickly and envelope your boat in a matter minutes. However, many recreational boats do not have AIS capability and the 20T USCG navigation buoys (that are not always exactly where they are charted) do not broadcast an AIS signal. So trusting your boat and your life to AIS displays in the fog is, IMHO, very dangerous. The ships and ferries have the right of way in all the narrow channels on the Bay and while they will do their best to avoid you when they are elsewhere, they frequently have a very limited ability to do so. AIS is one source of helpful information, but it is only one. And one that should not be relied upon for vessel separation in dense fog. I fear too many folks are not developing their skills with radar and general watch keeping because they are relying on AIS and chartplotter technology instead of taking personal responsibility to use all means to see and be seen in poor visibility situations.
Four days into a 21 day passage from Kauai to San Francisco, my wife and I were having breakfast in our cockpit when we encountered our first ship. I had set a five mile alarm ring on our AIS and it dutifully announced a 700 foot bulk carrier approaching our position. The CPA (Closest Point of Approach) was over a mile. We watched as the ship came into view.

Our ride that year was a 45 foot steel sailboat named Kaien. As most of us know, one of the advantages of a steel boat is that it has an excellent radar signature compared to fibreglass.

I hailed the skipper to let him know our position, course and speed. In a heavy Slavic accent and broken English the captain said that he was bound for Japan with a load of ore. I wanted to get a sense of how clearly he could see my radar signature, so I asked him:

“Captain, do you have me on radar?”

After a longer than necessary pause, the captain seemed a little irritated when responding almost as if I had insulted him.

“Of course I have radar,” he said.

“Yes, I understand, sir. Do you see me on your radar?”

Another pregnant pause and then:

“Wait a minute, I will go turn it on. I will call you back when I see you.”

Later we discovered some commercial crew compensation schemes provide incentives for keeping equipment in working order. The tests are done at the end of a long journey. Apparently, one way to keep mechanical equipment like radar arrays in working order is to use them as little as possible.

On another occasion, I was returning from sea singlehanded on a Tartan 3500 about to enter the San Francisco shipping channel. It was just after midnight and visibility was marginal with intermittent areas of fog and wind blown spray. Breaking waves on either side of the channel meant that I had few options to maneuver outside the channel to avoid traffic. I called VTS (Vessel Traffic Service) to announce my position and to ask about any traffic I might encounter. VTS said there was a tug towing a barge exiting the bay about to enter the ship channel. I did not have AIS on board.

Once I could see the two masthead white lights of the tug, I got on the VHF to arrange passing him in the channel. Given the conditions, it was difficult to judge his distance, but I could clearly see his running lights. I asked the captain if he could see me.

“No. I can’t see your running lights and you don’t come up on my radar. You should get one of those radar reflectors and put it up in your rigging,” he suggested.

Standing at the wheel, I looked up my mast and hanging off the port lower spreader was a metal octahedral radar reflector obviously failing to do its job.

There was no collision that night, but my faith in radar was shaken once again.
 

bgary

Advanced Beginner
Blogs Author
So trusting your boat and your life to AIS displays in the fog is, IMHO, very dangerous.

Spending a fair amount of my sailing time in the narrow (and busy) VTS lanes inside Puget Sound, I guess I'll suggest a middle path.

-- Do I "trust my life" to what I see on the AIS display? No. I don't "trust" any single source of info.

-- Would I rather have AIS information showing me other traffic than not have it? Yes, I want as much info as I can get.

...and it's icing on the cake if, along the way, that traffic knows where *I* am, too.

$.02
 

Pete the Cat

Member III
I was not suggesting that AIS was not useful. I am suggesting that anyone going into dense fog on SF Bay and relying solely on AIS for separation from other traffic is taking a big risk. I am also saying that radar, which admittedly will not work if it is off, and takes some practice to use effectively, is a vital tool for navigation in very low visibility situations. Radar doesn't work well in close quarters in large swells like the shelf off SF, or when someone does not turn it on. AIS doesn't work when you are in the fog with other vessels that are not also equipped or not broadcasting a signal. My view is that we should recognize the limits of all the tools we use for safety and use them all thoughtfully.

What has happened in Maine lately might be illustrative. The lobstermen do not generally broadcast AIS but are the most common vessel by far in Maine coastal waters--they work in very close proximity to each other and AIS alarms would be overwheming and ultimately meaningless to them as they circle their traps while pulling them--often within shouting distance of another lobster boat. In dense fog (which is more common there than in SF) they need to see and avoid each other in real time for close proximity avoidance. There are numerous narrow passages in Maine where you must have the ability to pass each other in a 50 yard wide channel. As more small recreational boats start broadcasting AIS, the alarms are increasingly less meaningful. AIS used to mean that there was a large ferry or freighter who would be restricted in its ability to maneuver in a channel or passage but now a small sailboat doing 3kts on a short tacking course can broadcast an AIS target and generate an CPA alarm.. Since the courses of small recreational boats are generally less consistent than larger vessels the AIS alarms can be numbingly inaccurate and actually misleading. Maybe I have poor quality software in my AIS, but the calculations of CPA seem broad and inaccurate in close quarters. I still use it, but with caution. AIS is a godsend on offshore passages if simply to give us the names of the vessels we encounter--I used to have trouble getting any response from ships offshore and have a healthy skepticism about their watchkeeping, but AIS identification seems to have made them at least answer calls to confirm crossing situations and that is another benefit of AIS.

SF Bay is not Maine, but the principles are the same. My view is that we should use all the technology available to avoid collisions but be mindful of the capabilities and limitations of each of them in different situations.
 

peaman

Sustaining Member
As more small recreational boats start broadcasting AIS, the alarms are increasingly less meaningful
Alarm conditions can, and should be, user-selected, based on anticipated operating conditions. The alarm function can be turned off entirely, in which case one can refer to the chart plotter or other source to learn where other vessels are. Broadcasting one's own own AIS signal is useful to others, whether or not the broadcasting vessel is watching for other traffic.
 
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