I figure out, the cruise of Second Wind was from any aspect seriously overkill .
this web. app. is free and the whole world, how cool is that.
......
webapp.navionics.com/?lang=en.....believe it goes as close as Garmin chart plotter
just download PLAN2NAV. by Jeppesen
Jeppesen charts, famous aeronautical charts, now marine too.
I tested app, and removed, unless you pay, you get bugger all.
/ and panning - zooming on iPad struggle /
sure screen dump on iPad and trim the edges
just sample Keppel rocks ..entrance Fitzroy Rivet.