2008 REED’s East Coast Edition - Communications
Satellite coverage of the world’s oceans var- manufacturers. Check the Inmarsat Website
ies from service to service. Generally speak- (www.inmarsat.com) for resellers and equip-
ing, the more expensive and comprehensive ment manufacturers.
the data services offered, the broader the Inmarsat-C was developed as a low-cost
range of the service’s coverage is likely to be. SatCom suitable for fitting on any vessel. The
However, many of these higher-end, very system’s size—slightly larger than a car radio
expensive services are directed at commercial with a small omnidirectional antenna—and
and industrial users located in places the av- weight make it especially suitable for yachts
erage yacht is unlikely to ever go. and fishing vessels This system does not pro-
Even with all of the advanced capabilities, vide voice communications, but it does send
SatCom systems are easy to operate and text messages (fax/e-mail) rapidly.
don’t require the protocols required for VHF, Subscribers do not have to use a service
MF, and HF(SSB) radio. If you can operate provider in their own country. Most provid-
a telephone, cellular phone, fax, or PC, you ers offer Internet e-mail connection and reg-
can operate any of the Inmarsat and other ularly updated weather reports, stock market
SatComs. Several SatCom models are avail- information, medical information and news.
able for each Inmarsat standard and for Inmarsat-C is GMDSS-compatible and
other satellite systems. In most cases, these is used to transmit SafetyNET messages,
consist of an above-the-deck stabilized auto- much like NAVTEX messages. Its automatic
tracking antenna encased in a small weath- distress-calling feature, with fast and reli-
erproof dome. Below decks is the electronic able alert calling to the Rescue Coordination
and peripheral equipment such as a phone, Centers (RCC) in closest proximity to the
and computer. vessel in distress, is unparalleled.
For global cruising, SatComs can provide Inmarsat also has the A, B, and M systems
both safety-at-sea and business communi- (for large vessels) and the Inmarsat Mini-M
cations, but should not be considered as a that provides voice, fax and data service, and
replacement for VHF, MHF and HF (SSB) uses a stabilized five-pound tracking antenna
inter-ship and ship-to-shore hailing or (9.5” high and 8.5” in diameter).
navigation channel communications. Radio Inmarsat’s new Fleet F33, F55 and F77 pro-
communications are not only required by vide phone and data service at broadband
regulation for this purpose, they are eco- speeds. F77 is GMDSS compatible and has
nomically the most efficient when within global coverage but requires larger, more
range of other vessels and coastal facilities expensive equipment (antennae average 2.5
that are serviced by radio telephone. Howev- feet diameter). F55, suited for smaller, recre-
er, for consistent global communications and ational yachts, has global voice coverage and
distress calling not affected by atmospherics spot beam data service (antennae average
and radio propagation effects, SatComs have 21 inches diameter). Both F55 and F77 offer
few peers. data speeds up to 64kps, and can be accessed
Generally, the dealer or distributor from via ISDN (in which you pay for the time con-
whom you purchase SatCom equipment will nected) or via MPDS (in which you stay con-
assist in the commissioning and registration stantly connected and pay for the amount of
process after purchase. Be careful, though, data transferred). F55 and F77 include op-
because some dealers are not fully versed in tions for 9.6kbps or 64kbps fax service.
the commissioning requirements. Because Iridium (www.iridium.com) and Global-
there are economic choices to be made in star (www.globalstar.com) are two private
selecting equipment and a service provider, a companies offering satellite phone service
specialized SatCom consultant’s advice may designed to work in conjunction with cell
be helpful. networks. Both offer voice and data services.
The International Maritime Satellite Orga- Although both Iridium and Globalstar
nization operates several different systems. promise service anywhere, their actual ser-
Their newest generation offers broadband vice areas do not include large swaths of
internet access up to 432kbs. INMARSAT ocean outside the common sea lanes. Check
services are sold through independent resell- their coverage maps against your needs be-
ers and require equipment made by separate fore signing up.
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