Hello. I'm trying to view your mti_ak onto my echomap unit. I can see it, but only at certain zoom levels, like 5mile-30mile. It varies depenging on the gps units detail setting. At highest detail you lose the view at 50 mile range.
The issue is it has no usable detail, like you see in basecamp. Also garmin unit says the map cannot be authenticated and will be diabled in 90 days.
The vessel is a hovercraft and travels in areas up the river near AMBLER AK where regular charts show nothing. Your chart, at least in basecamp shows the area pretty well, see image. I've also attached pics of the highest detail I can get of your chart on the gps(nothing really). Thanksambler via mtiak.pngambler via in echomap.png