Tradeoffs between satellite systems

Satellite Systems, Handsets, and Hotspots

The Iridium GO! has the cheapest data plan. Plans vary so be sure to shop around. Among other

Iridium GO!

Iridium GO!

airtime vendors, check the prices at www.OutfitterSatellite.com     Iridium units and Inmarsat isatphone have different strengths and weaknesses. Iridium’s satellites are in low-earth orbit (LEO’s) and are relatively close, meaning strong signals and an easier connection from you to the satellite. Being in low orbit they move quickly relative to the earth and sometimes data calls are dropped. Inmarsat uses geostationary satellites, which will always be in the same location in the sky, but are much farther away which means weaker signals and slower speeds but fewer dropped data calls.  Globalstar uses low satellites but only works when a satellite is in simultaneous view of both the vessel and a shore station.  This limits Globalstar’s coverage to within a few hundred miles of shore, in spite of the name.

In any case, a proper external marine antenna is important, located where it has a clear view of as much sky as possible.

There are three choices for Iridium products, the GO!, the 9555 and the 9575 “Extreme” ruggedized phone. The GO! has the cheapest data plans but is fiddly to use for phone calls

Iridium Extreme in a dock

Iridium Extreme in a dock

because it requires the additional use of an iPhone connected via wireless.  The Iridium 9575 Extreme is handier in an emergency. The Extreme can be used by itself to make phone calls and is water resistant.  Both the Iridium Extreme and the GO! contain GPS and GEOS emergency button. So if your Extreme or GO! is registered with GEOS (free), you can press the red button, and folks on your registration list, as well as SAR authorities, will be forwarded your location and your request for help.

Most folks go with Iridium over Inmarsat and Globalstar, and most folks select the Iridium GO! unless they want a device to also be handy to make calls in an emergency, in which case they buy an Iridium Extreme and pay higher data rates.

Data communications costs about $60 per megabyte over Iridium, unless you pay $125 per month for the unlimited data plan on the Iridium GO!.

Wide Bandwidth Satellite Dome Systems

Inmarsat FB150

Inmarsat FB150

The Inmarsat Fleet Broadband 150 is a 13 inch dome that provides 150kbps data at $25 per megabyte, with nearly worldwide coverage.  Inmarsat also has a “Fleet One” version of this system but it isn’t useful due to its limited coastal coverage.

The KVH V3 is a 14.5 inch  dome that provides 300kbps data at $1 per

megabyte with coverage of any place that a sensible cruiser is likely to go.

KVH V3

KVH V3