You will never get the value of installing an air conditioner back - first, you can't run them while underway or at anchor
(unless you have a LOT of fuel
for generators). Some marinas
meter the amount of electricity you use, so for a summer of immobility you could install a 6000 Btu window-mounted unit (out of WalMart or Sears for less than $200)...
You don't mention whether you have an HF system or not, so I suspect you don't. They are a fair amount of money
up front, and a learning
curve, but there are many nets for info and conversation, and Winlink is free for email
for Hams. Iridium is less expensive up front but has continuing (monthly-ish) expenses for use, even just for enrollment with no use. But there is almost no learning
curve and they are very handy in an emergency
. HF radios let you talk on "party lines", sat phones are just one-on-one. There really isn't a clear choice, it depends on how you expect to use them, the resources of the people you want to contact, your budget
, your willingness to get involved in electronic systems or cruising communities...