..have never understood why the USA insist on being, not just different from the rest of the world ("International") but Canada also?!?
Far be it from me to excuse anything done by the country to the south of us in the Great White North, but they and we do have a need for more simplex, and fewer duplex, channels than are internationally defined. Then again, the US went and auctioned off their duplex telephone channels.
We also deal with some legacy spectrum planning issues, like the first few channels having belonged to the railways in parts of Canada. And there's the matter of a great chunk of both countries being, er, rather far from any coastline.
I teach the Restricted Operator's Certificate (Maritime) course for our local squadron, and even I find that the matrix of channels/areas/users/authorized-uses is, well, convoluted to say the least.
On topic, I have a SH GX2150 (with AIS, without GPS) hooked up to both ship's GPS (to radio) and chartplotter (from radio) and am very happy with it. The radio *and* its remote mic both have a simple and easily readable display of nearby AIS targets with vectors, and you can call up additional detail on any, as well as call them directly by MMSI. The display is small but uncluttered, to the point where it's often easier to see than the targets on the chartplotter hidden amongst all the other info.