NASA AIS transponder

[Peter Gazzard]

Hi guys and gals looking to purchase an ais transponder.Are they any good and do u need more than just transponder gauge and are the compatible for Aust wiring.As I understand it,it uses onboard gps system.
Look forward to your input.

[Peter Gazzard]

Comments on nasa Ais transponder please

[tkeithlu]

I got hooked on AIS by my brother-in-law, a ship pilot in Aransas Pass/Corpus Christi. I won't leave home overnight without it. The free standing unit will cost about $400, and needs GPS and VHF antennas. Mine are dedicated, but I think you can share. It gives you a screen with other boat/ship symbols and nav markers, tells you who to call and them who you are, and calculates collision and nearest point of approach for you - sort of a super radar. My B in L kept sending us Google Earth screen shots with our boat marked on our last cruise. The nearby stuff is done by VHF, but the information also goes by satellite, so if you want an idea, Google "AIS map." My only objection has been boats leaving them turned on while in marinas, so I get a bunch of collision alarms when passing by in the channel.

[Hydra]

I have a Watchmate 850 AIS transponder with B&W display, internal GPS receiver and dedicated VHF antenna. At about 1000€, it's not cheap but works well.

Having seen the low price of NASA instruments, I checked their reputation for reliability and durability. It was not good enough for me.

Alain

[clownfishsydney]

The cheapest AIS I could find in Australia was the GME 120 series. I purchased the transponder and antenna splitter from Whitworths. Currently it is under AUS$770 for both. Never seen or heard of the NASA one.

AIS is great, we found it very useful last year when we sailed from Sydney to Northern Queensland and back. The GME one has a built in GPS, all I did was mount it below a window and it gets perfect satellite coverage. Easy to link into chartplotter and laptop.

[Hydra]

It seems that NASA AIS devices are only *receivers*, not *transponders*: AIS Archives - Nasa Marine Instruments
They do not broadcast messages to make your boat visible on other receivers.

After choosing between transponder and receiver, the second thing to decide is whether you want one with an integral display or a "black box", to be connected to a computer or a chartplotter.

I decided for the standalone capability.

Alain