AIS Receiver or Transponder

[Auspicious]

Splitters are evil. Bad idea. Move on.

[rodney_k]

I just installed the AMEC Camino 101 aboard my boat. Great unit and works as advertised. This transponder can use an external GPS. If you go that route, make sure your GPS can output RMC, GGA, GSA, and HDT nmea. 0183 sentences. My Standard horizon CPV-350 did not output all of these sentences so I installed the companion AMEC GPS antenna. The Camino 101 in connected to a 3db VHF antenna mounted on the radar arch. The antenna is about 10 feet above the water. Not sure about transmit range but the unit consistently receives 50 to 60 targets here in SF Bay.

[nhschneider]

We installed the Garmin AIS transponder that essentially comes with a splitter built in. Not only that but we installed the GPS antenna under the deck and it works great.

Fair winds and calm seas.

[barnakiel]

Originally Posted by rodney_k

(...) Not sure about transmit range but the unit consistently receives 50 to 60 targets here in SF Bay.

Class B you are limited by output power. Class A targets you will see from way away. Class B within a shorter range.

Wiki: "Class B (...) To prevent overloading of the available bandwidth, transmission power is restricted to 2 W, giving a range of about 5–10 miles ..."

Cheers,
b.

[rodney_k]

Originally Posted by barnakiel

Class B you are limited by output power. Class A targets you will see from way away. Class B within a shorter range.

Wiki: "Class B (...) To prevent overloading of the available bandwidth, transmission power is restricted to 2 W, giving a range of about 5–10 miles ..."

Cheers,
b.

510 miles with 2 watts at VHF frequencies? Must be a typo. More like 10 miles maximum unless there is tropo ducting taking place. I am unsure of my transmit range only because I haven't had the opportunity to test reception with other class B equipped boats in my area. I will not bother class A equipped shipping with requests for reception reports.

My boat does show up on marinetraffic.com. I am about 6 miles from the nearest marinetraffic.com receiver so transmit is probably OK.

Regards,
Rodney
K6YOT

[barnakiel]

Originally Posted by rodney_k

510 miles with 2 watts at VHF frequencies? Must be a typo. More like 10 miles maximum unless there is tropo ducting taking place.

;-)

Sure.

Yes, an obvious typo. Correct value: 5 (five).

b.

[mbianka]

Originally Posted by rodney_k

I just installed the AMEC Camino 101 aboard my boat. Great unit and works as advertised. This transponder can use an external GPS. If you go that route, make sure your GPS can output RMC, GGA, GSA, and HDT nmea. 0183 sentences. My Standard horizon CPV-350 did not output all of these sentences so I installed the companion AMEC GPS antenna. The Camino 101 in connected to a 3db VHF antenna mounted on the radar arch. The antenna is about 10 feet above the water. Not sure about transmit range but the unit consistently receives 50 to 60 targets here in SF Bay.

Good to know. I'll probably go the same route too. Thanks.

[CarlF]

Definitely choose the transponder. Besides the advantages already mentioned, it allows commercial ships to hail you by name instead of the useless "white sailboat on my port bow". In crowded waters, many ships will hail if there's any questions. Hitting something, regardless of fault, is normally a career ending event for a ship captain.

I've used a splitter with no problems for three years. Like many bits of new boat technology, early versions seem to have had problems that are still being recounted long after better units have appeared. These are very simple pieces of equipment, probably less likely to fail than the AIS unit.

Using a mast head location for the AIS antenna will substantially increase both your receive and transmit range. Regardless, be sure to use low loss antenna cable. The cheap cable often used really hurts range.

I got my equipment from Milltech Marine. Very knowledgeable group. They could give you the most up-to-date "yea or nay" on splitters.

Carl

[Auspicious]

Originally Posted by CarlF

I've used a splitter with no problems for three years. Like many bits of new boat technology, early versions seem to have had problems that are still being recounted long after better units have appeared. These are very simple pieces of equipment, probably less likely to fail than the AIS unit.

Splitter technology is by no means new. Low loss splitters are available but quite expensive. The ones you can buy for marine application are poor performers.

Remember 3 dB is HALF YOUR POWER.

[David M]

Considering the speed difference between a fast ferry (maybe 30 knots) and a sail boat (maybe 6 knots) It is better to be seen than it is to just see. There is not a whole lot of hope of getting out of their way when they are in a harbor making frequent course changes.

I prefer a dedicated AIS antenna. It's more reliable and it never has to be shared which is better to have. The range you get at deck level with an AIS antenna is plenty good.

[xymotic]

I don't even understand the definition of 'fast' Even here in the relatively confined quarters of Puget Sound friggen container ships are routinely in the 20's Often high 20's. People think of them as some slow lumbering beast, they are all of the above except slow!

[jr_spyder]

I did a full electronics retrofit on my boat over the winter including an AIS transponder. Had my first valuable experience last week in a relatively narrow channel in Narragansett bay with an ocean tug/ barge ahead of us. It was that time of evening when the light was such that we couldn't exactly make out the vessel. While discussing this we got a call on our VHF, using our name, from the watch on the tug. We discussed how to pass. Simple but brilliant. Had to love it.

Of course it also taught me to use this new kit - I had forgotten it was right in front of me! My wife and I were using our old and familiar routine "Whatdayathink? I donno, whatdauthink?". AIS is better!

[David M]

Us commercial guys make passing arrangements with each other all the time on 13. It seems most of the time the pleasure boaters never answer the radio when I try hailing them. It would be nice if more pleasure boaters joined us to let us know their intentions. Channel 13 is the place to do this. You will have much better luck on 13 than on 16. We all realize 16 is the hailing channel, but in reality it does not always work that way. Always try 13 first with commercial vessels.

[perchance]

For what they cost two vhf radios make sense. One on 16 the other 13. Just a thought.

[xymotic]

Originally Posted by perchance

For what they cost two vhf radios make sense. One on 16 the other 13. Just a thought.

Two radios is indeed very nice, but I have to say I'm AMAZED at how many people can't use what they already have!

Just about every recent radio has a dual or tri watch function.

radio on 13 to talk and you can still monitor 16 when needed.