I cruised from Florida to Maine this year and found that unsecured WiFi was rarely available. There were plenty of WiFi stations with decent signal strength but they were always secured. Once when anchored at Miami Beach I saw dozens of WiFi stations, but all were secured. Miami Beach residents are particularly paranoid it seems.

I relied upon a Verizon Aircard for most of my internet communication. I had a fast connection (about 500 KB/S) about 70% of the time and a slow one (100 KB/S) about 25% of the time. The balance, 5%- mostly in NC and Maine, I had no usable signal.

For WiFi I had a very good amplifier and a low loss cable to an external antenna, so signal strength was not a problem, but security was.

David