Thank you everyone for the advice so far. Harry, I'll drop you a note
when we get further along with our plan. Herrington Harbour marina is
supposed to have a good WiFi service (BeaconWiFi.com). Grandma
Rosalie, as usual your advice and recommendations sound very thorough
and thoughtful. The secret to getting good WiFi service at anchor or
on a mooring is altitude. My adapter is 20 feet off the water and
piped into the main cabin vis a USB hub on the flybridge. Keeping the
hub and cable connections dry is a major engineering challenge since
none of the first three liked rainy days very well. The adapter itself
is double wrabbed in zip lock bags and seems to do OK.

I was mildly surprised to see Baltimore on the list. Is there really a
good cruising destination there, and if so, whereabouts? I've always
thought of Baltimore as a busy commercial harbor not particularly
friendly to pleasure boats but I'm open to being re-educated.