The VSAT solutions provide limited global coverage - a fact there are undergoing changes since the number of planned satellite for VSAT service is increasing. All mayor shipping lanes are well covered by VSAT
Neither systems cover the North or South Pole respectively - the coverage is at about 70 degrees North / South. The satellites which for these two types of systems are geostationary are positioned over the Equator at approx. 36.000 km altitude and due to the distance they can not provide coverage of North and South Pole.
There are major differences in the accounting terms and conditions between the two systems. Inmarsat FleetBroadband system is 'pay by usage' - meaning that you pay for the data volume sent/received via the satellite or the telephone. The VSAT system is accounted as a fixed monthly fee. This means that you always know the fee per Month independently of how much you utilize the terminal.
Telephony over the VSAT system can be supplied as a so called VoIP solution (voice over IP) - to very favorable prices, which are billed separately.