Buy the best cell phone
amplifier (i.e. a Wilson booster) and good omnidirectional antenna
that you can. Put it on your boat. That will boost your cell phone
connection (voice and data) and you should find good coverage, assuming you have a good carrier, all along the coast.
range off the coast was limited by carrier system design, so that at 32 miles your signal will be ignored even if you have one. In practical terms even at ten miles out you'd be lucky to get any signal simply because few carriers waste their money
looking towards the empty [sic] sea. But you'll get far cheaper faster coverage with cellular than anything else.
can be problematic, because if you're using open Wifi connections, they are security
risks. If that's news to you, check online for white papers on that, and have your wife ask her IT department for a quick education on that. On the east coast
of the US, with all the wireless plans available today, the WiFi booster is a nice idea, but since the connection is going to be a necessity, it might be worthwhile to get cell phones from two different carriers, so that if one doesn't cover a particular area, the other very well might. (i.e. Verizon versus T-Mob or AT&T.)
The cell phone booster also has to be chosen to make sure it supports both the carrier and the type of service
(LTE, 2G, high band, low, etc.) that the carrier supplies, the cheaper ones tend to cover only one or another, not all.