AIS Cheap VHF Ship Alarm

JohnShannon · Nov 8, 2018

Cool! But what is the ships name? what is the ships speed and heading? Are they on a collision course or not?
In SF Bay we have hundreds of AIS sources, nice trick for the middle of nowhere if it works. Alternatively SH GX2200 radio here at the SBO store for $399. Gives you GPS and AIS in one handy package beeps if you are about to be run over.

jssailem · Nov 8, 2018

I have a SH GX2200.. Great radio.

Joe · Nov 9, 2018

StargazerP303 said:
Found this online! Has anybody tried this?
AIS Cheap VHF Ship Alarm
Hardware required: VHF: Turn your VHF on and set it to channel 87 or 88. So you also monitor channel 16 press the dual scan button. Turn the volume up and set the squelch to fine. A burst of sound will tell you that a ship is within VHF range. It’s as simple as that.
Capt Rob

https://opencpn.org/wiki/dokuwiki/d...pplementary_hardware:ais_cheap_vhf_ship_alarm

"Has anybody tried this?" uh.... no. Dude, someone's pulling your chain.

dlochner · Nov 9, 2018

AIS broadcasts on 161.975 and 162.025
Channel 87 is on 157.375
Channel 88 is on 157.425

I don't think it will work.

https://www.navcen.uscg.gov/?pageName=mtvhf

Pirate Dave · Nov 9, 2018

Wow an April Fools joke in November.

Who told you that it would work? Dr Sloo F Lirpa ????????

JohnShannon · Nov 9, 2018

Thank you Dave! real information.

jeepbluetj · Nov 9, 2018

In the scheme of boat dollars, $400 for a SH GX2200 is an absolute bargain. I've even contemplated replacing my GX2150 with one just to get the integrated GPS for redundancy.

Brian D · Nov 9, 2018

dlochner said:
AIS broadcasts on 161.975 and 162.025
Channel 87 is on 157.375
Channel 88 is on 157.425

I don't think it will work.

https://www.navcen.uscg.gov/?pageName=mtvhf

It would appear that at one time, it may have been called 87B and 88B but have been changed to AIS1 and AIS2.
https://www.marineinsight.com/marin...nd-identifying-marine-communication-channels/

jssailem · Nov 9, 2018

@jeepbluetj i am happy with my purchase.
Check out https://www.thegpsstore.com/Fixed-Mount-VHF-Radios-C386.aspx
$307.
SBO has them for $399 Give @Dave Groshong a shout. Maybe he can make the purchase worth your effort.

capta · Nov 10, 2018

Yeah, way to make a quiet pleasant day out on the water into a hellish noise filled nightmare; turn your radio on full blast and monitor ch 16 in a dual watch configuration just to find out there is another vessel in the vicinity!
All that for the ships name, which I couldn't care less about, it's speed, heading, and whether we are on a collision course or not? The important bits of which every one of us should be able to determine w/o AIS if we are in sight of another vessel.

dlochner · Nov 10, 2018

StargazerP303 said:
The problem with Standard Horizon AIS is the boats over time JUST Disappear from the system. I was at the Annapolis boat show 2 years ago. At the Standard Horizon booth, The rep told me they were coming out with the new Rec-Xmit AIS radio. I was told after following up 1 year past, that Japan was having Patent problems. In year 2 I called the same message FCC not approved yet, Patent issues. I called FCC to find out it's not true there was not an application applied for by Japan or Standard Horizon. Another word, Hipe! They even had a unit at the show but not working..lol
I call Horizon and told them to remove the radio from the website until the said time, they had an actual unit for sale.
I also see that youtube has an actual AIS problem to see..
YOU! should not trust a radio that shares VHF/AIS with ONE antenna.
SEE LINK:

If you need AIS then purchase just AIS with its proper AIS antenna. TX and RX. This is my opinion!
Capt. Rob

Check the AIS filter. In order to reduce screen clutter some AIS units will not show vessels that do not present a collision threat. Remember AIS was initially designed to reduce collision threat with commercial vessels, i.e., freighters maneuvering in close quarters and restricted visibility such as harbor approaches and at night.

To be honest there are very few boats in my neck of the woods commercial or recreation with AIS so I haven't messed with the filters on my Vesper XB8000. As I recall though there is a setting that hides vessels when their Closest Point of Approach (CPA) exceeds a set value. When a vessel gets within 1 mile I do get an alert that goes away when there it is more than a mile distant.

Having a single AIS/VHF antenna means having a single point of failure for the AIS and VHF. The upside is there is one less thing at the top of the mast. A well designed antenna splitter matched for the AIS allows for the combined use (and adds FM broadcast reception). The Vesper Marine AIS systems are highly regarded.

Brian D · Nov 10, 2018

Do you really need AIS? Or, do you want to keep up with the Jones' and add AIS? Need vs want! I would rather have radar than AIS any day of the week. Is AIS the new LoJack?

Davidasailor26 · Nov 10, 2018

StargazerP303 said:
I also see that youtube has an actual AIS problem to see..
YOU! should not trust a radio that shares VHF/AIS with ONE antenna

I don't have any experience with the SH radio in the YouTube link, but I disagree that there's any inherent problem with an integrated VHF / AIS receiver. We have a Simrad RS35 that has no problem showing consistent contact with AIS transmitters up to 40 miles away, more for big cargo ships. Targets don't randomly disappear, and we can receive VHF audio from just as far just as consistently. We did have a problem earlier this year with a bad antenna connection, and that led to loss of signal over about 10 miles. Once we fixed the connection we were back up to 40 miles. My guess is that the radio in the YouTube clip is suffering from similar antenna issues, possibly worsened as the radio warms up.

I agree that there are no solutions to transmit AIS integrated with a VHF. It would be nice if a manufacturer could get that working.

Davidasailor26 · Nov 10, 2018

capta said:
All that for the ships name, which I couldn't care less about, it's speed, heading, and whether we are on a collision course or not? The important bits of which every one of us should be able to determine w/o AIS if we are in sight of another vessel.

To each their own. Personally I like being able to "see" a little further away or around a bend. And I do like seeing the other guy's name, either to make hailing easier or, in the case of megayachts, just out of curiosity.

dlochner · Nov 10, 2018

Brian D said:
Do you really need AIS? Or, do you want to keep up with the Jones' and add AIS? Need vs want! I would rather have radar than AIS any day of the week. Is AIS the new LoJack?

I have both and at the moment little need for either. However, if the planets align correctly we will be taking off on an adventure into fog laden waters with some night passages. So, I have both now to learn how to use them.

AIS has 2 functions, to be seen and to see. Radar only allows one to see. In poor visibility I want the big boys to see me clearly. Radar can be a bit iffy but AIS is right there unless the ship has the class B filter turned on.

MARPA on a radar unit can perform similar functions as AIS, in that it can track and plot the path of a moving object, but it requires expensive hardware to work correctly and in a bouncing boat may not be as accurate as a broadcast GPS position.

capta · Nov 10, 2018

dlochner said:
MARPA on a radar unit can perform similar functions as AIS, in that it can track and plot the path of a moving object, but it requires expensive hardware to work correctly and in a bouncing boat may not be as accurate as a broadcast GPS position.

If one is going to be using and relying on Radar, I would highly recommend the USCG certified course for radar observer. Unlike most USCG courses for licensing, this one actually teaches one valuable information on using, plotting and interpreting radar returns, rather than just preparing one to pass a test.

Brian D · Nov 10, 2018

dlochner said:
...
AIS has 2 functions, to be seen and to see. Radar only allows one to see. In poor visibility I want the big boys to see me clearly. ...

In the case of AIS, you might be right assuming one's transmitter is working. In the case of radar, this would be correct if one did not employ a radar reflector. So neither case one is 100%.

When leaving San Diego Harbor I was picked up by a Navy ship 8000 yards away. I could barely see the super structure with my binoculars let alone a ship. I suspect he saw me because of my radar reflector. But I am not 100% sure. Had I had AIS I might not have seen him at all because war vessels do not broadcast on AIS to the best of my knowledge.