we have both an inmarsat mini-m and a globalstar on board. the mini m also downloads faxes and internet.
the mini-m has worked in a number of gales and a storm with waves over 30 feet. the globalstar doesn''t lock in in these conditions offshore. we never tried to use it down below. you can rent one for a week or more from gmpcs if you want to try one out. we keep the globalstar in our bail out bag for the life raft.