AIS GPS Location

[Bob S]

The Defender Warehouse sale is here and I am ordering a Vesper XB-8000 at a great price. I have to fill out a program sheet asking where the antenna will be located on the boat. The problem is I am not sure yet. I'm sure I'm not the first to be in this predicament. I have my Garmin GPS located on the port pushpit so I was thinking of installing the AIS GPS on the opposite side but I saw a how-to video and the base is designed to mount flush to a flat surface so now I'm thinking of the top of my Nav station inside. I have a Bluetooth GPS puck that I've used for my older iPad that has worked flawlessly in that same location. Anyone see any issues with that? How accurate do I need to be with the A,B,C & D dimensions on the program sheet? My guess is if I were a 200' fishing vessel then the mounting location would be more important than a 39' sailing vessel.
Any advise is appreciated!!!

 

[S/V Talisa]

Bob, if you are not aware, this is an issue caused by US bureaucracy which says that you are not allow to have the programming software to set this up yourself (only a 'trusted dealer' can do it). The thinking is that you could 'pretend' to be someone else on AIS and Uncle Sam doesn't like that idea. Leave aside the fact that anyone with serious bad intent can get around this in a heatbeat and nowhere else in the world imposes this restriction.

However, I digress... if I were you, I'd make a guess at the centre point of the boat, you aren't going to be that far off. Although it's technically correct to input the exact antenna location (and therefore the position fix that gets transmitted), you are right that this matters a whole lot more on a cruise liner or supertanker than a yacht.

Be aware though that with a lot of these AIS units, programming the MMSI and other details is a one shot deal and changing afterwards usually means the device has to be returned to the original manufacturer for service.

Duncan

 

[dlochner]

The Defender Warehouse sale is here and I am ordering a Vesper XB-8000 at a great price. I have to fill out a program sheet asking where the antenna will be located on the boat. The problem is I am not sure yet. I'm sure I'm not the first to be in this predicament. I have my Garmin GPS located on the port pushpit so I was thinking of installing the AIS GPS on the opposite side but I saw a how-to video and the base is designed to mount flush to a flat surface so now I'm thinking of the top of my Nav station inside. I have a Bluetooth GPS puck that I've used for my older iPad that has worked flawlessly in that same location. Anyone see any issues with that? How accurate do I need to be with the A,B,C & D dimensions on the program sheet? My guess is if I were a 200' fishing vessel then the mounting location would be more important than a 39' sailing vessel.
Any advise is appreciated!!!

The part you are not allowed to program is the MMSI number. I have the Vesper unit and if I remember correctly you can change the location of the antenna. If the location is not accurate not much is going to happen on a 39' boat. If you are using the GPS to navigate to +/- 20' I think you have other problems, mostly with judgement. On the other hand, if the vessel is a 1000' ft container ship, the antenna location is a big deal.

 

[jssailem]

Dave is correct. Dealers recognize that the MMSI programing is a onetime shot, or the unit is coming back to the dealer for correction. So they request the MMSI number get issued so that it can be programed. The CG do not care who does the programming. They do care that the AIS be programed with a valid MMSI before use. AIS transmission only works if you have a valid MMSI.

That said, Vesper allows the rest of the data to be programmed by the owner using the system software. GPS location on a 30 foot sailboat cruising at 5 knots is one of those nice but not relevant issue. If your on a 300 ft long and 75 ft wide ship traveling at 20 knots now it becomes significant as the data is used to calculate CPA (Closest Point of Approach).

 

[All U Get]

Bob, if you are not aware, this is an issue caused by US bureaucracy which says that you are not allow to have the programming software to set this up yourself (only a 'trusted dealer' can do it). The thinking is that you could 'pretend' to be someone else on AIS and Uncle Sam doesn't like that idea. Leave aside the fact that anyone with serious bad intent can get around this in a heatbeat and nowhere else in the world imposes this restriction.

However, I digress... if I were you, I'd make a guess at the centre point of the boat, you aren't going to be that far off. Although it's technically correct to input the exact antenna location (and therefore the position fix that gets transmitted), you are right that this matters a whole lot more on a cruise liner or supertanker than a yacht.

Be aware though that with a lot of these AIS units, programming the MMSI and other details is a one shot deal and changing afterwards usually means the device has to be returned to the original manufacturer for service.

Duncan

Somebody ought to pass that along because I'm pretty sure a few cruisers I know have done their own, I'll check but you won't hear back if they did.