Satellite Communications

Satellite Communications. Options for communicating on a boat and out of VHF & cell phone range include Satellite and SSB. SSB can get you some very cheap air time after the initial start up costs. However new developments in satellite technology is making this option cheaper.

To give you an idea of costs a cell phone call from the Bahamas to the US may cost more than a sat phone call. Satellite phone costs vary from close to $1/minute to $1.5/minute, so if you use the phone sparingly it’s not that expensive.

Satellite CommunicationsSatellite Communications

One new feature from satellite providers is free incoming text messages to subscribers via web site. This works by a party going to say the Iridium messaging site and entering their friends Iridium phone number and typing in a message. The text message then appears on the Iridium phone within a few minutes.


Phones are obviously for voice communications; however some data transfer is available.

To aid in this data transfer you can use data compression services like MailaSail and Sailmail and provide E mail and compression services. In the last ARC Atlantic rally Yachting World reports that MailaSail and Sailmail were the two most popular services.

Phones need a line of sight and so for use below deck you should invest in an external antenna and wire it to down below

You can also rent Phones

Iridium Phone

Iridium uses a constellation of 66 satellites. The number 66 is the atomic number for iridium. The satellites use a LEO orbit.


Iridiums latest phone the 9555 comes with full global coverage and voice and data capability at a reasonable cost considering the benefits.

Iridium phones have their own numbers like they are their own country. The 12 digit numbers beginning with 8816. Calls from landlines or mobiles are expensive and to save on expensive calls use two-stage dialing. This involves calling a routing service in the USA and entering the Iridium phone number you wish to contact. The caller will pay the call to the routing service, and the Iridium phone-holder will pay for the satellite portion of the call.

The data speed is still only 2,400 bps, so surfing the web will be slow and e mails sent judiciously. However employing XGate or OCENS to compress data will be a great benefit. The new USB port allows easy connection.

Services Provided; Voice, slow data

Hardware Costs; Iridium 9555 retail around $1,500

Service Costs ; call costs of $1 for iridium to iridium and $1.5 for iridium to PSTN, (public switched telephone network).

Coverage; World wide coverage, due to 66 satellites

Inmarsat isatphone

The new isatPhone Pro provides telephone, voice mail, text messaging and e-mail. Hands-free operation via Bluetooth is built in. Cost around $500 with airtime plans starting at $20 a month plus around $1/minute.


Services Provided; Voice, SMS and basic email

Hardware Costs; IsatPhone costs around $500

Service Costs ; calls cost around $1/minute

Coverage; Map


Satellite Antenna

For more data and ability to surf the web and even video you need an Omi Directional antenna. The reason for this is so you can get to the GEO satellites which are a long way away.

Iridium Pilot

Iridium provide data transfer beyond the phone. Open Port and Iridiums Pilot have a small antenna that can Iridium “Pilot keeps ships connected everywhere on the planet”

Iridium PilotIridium Pilot

Service; Data Up to 134 kbps bidirectional with Iridium OpenPort broadband service. Antenna size; 9 Inch dia

hardware Cost; $4,900.00

Coverage; Global, pole-to-pole

Testimonial Round the World Vendee Globe racers use Iridium Pilot IMOCA 60 communications

MCLEAN, Va., May 30, 2012 — Iridium Communications Inc. is providing vital satellite broadband communications for the IMOCA Championship. Twenty sailboats will be equipped with Iridium Pilot™ terminals, the new Iridium maritime broadband platform, as part of the telecommunications package provided by Geolink, a long-time Iridium partner and innovative race communications supplier. Relying on the world’s only truly global satellite network, skippers and crews can access real-time weather reports, sailing conditions, benefit from an emergency communications safety link, and stay connected to family and friends via phone, email, Facebook and Twitter throughout the race.

Inmarsat Fleetbroadband

Sailor 500 on Volvo 70Sailor 500 on Volvo 70

Inmarsat Operates four GEO satellites to provide phone, fax, and data to anywhere in the world, the poles excepted. Originally built by a consortium of countries, Inmarsat was privatized in 1999.

FleetBroadband; is the latest from Inmarsat. FleetBroadband antenna come in FB500, FB250 and FB150. FleetBroadband 150 is the smallest service from Inmarsat, with 150 Kbps, the data speed. Antenna sizes are around 11 inches diameter and weigh only 9 lbs. The stabilized antenna rotates 360 degrees, and down for pitch and roll. The picture shows a Volvo 70 round the world racer which uses a Thrane & Thrane Sailor 500 to provide not only communications, but streaming video.

Services Provided; phone, fax, and data

Hardware Costs; Cost of the FleetBroadband system is varied. The sailor costs around 5,650 Euros, or close to $8,000 US. Skipper 150 has a price under $5,000 and also claim better features check them out at Skipper 150 FleetBroadband solution

Coverage; Worldwide the poles excepted.

Hardware Providers; KVH, Thrane & Thrane Sailor, Skipper from AddValue

FleetBroadband 505 emergency call Good news for Inmarsat and FleetBroadband users is the new 505 emergency call service. Due to come into effect on October 1st 2009 the new service allows users to connect directly to a coast guard rescue center. These centers are called RCC for rescue co-ordination center and operate 24/7


VSAT terminals are very sophisticated and hence expensive. They cost more than Inmarsat and Iridium or sat TV, but do offer unlimited airtime and data reception rates as fast as 2 Mbp.


The picture shows a KVH Trackphone V7 (24″ dome) setup on a 130ft Westport. This is the personal boat of a NFL football team Owner. He needs lots of data communications so he is OK with the very high startup costs and the monthly fees he gets with the V7 VSAT antenna.

Press Release; “KVH Industries, Inc. today introduced a new type of satellite communications service that enables small, 24” antennas to provide affordable, “always on” broadband data connections to vessels. The new mini-VSAT Broadband service uses sophisticated spread spectrum technology to provide vessels with data reception rates as fast as 2 Mbps and data transmission rates as fast as 512 Kbps via a 24″ KVH-developed marine terminal. To support this service, KVH, under a joint development agreement with ViaSat, Inc. , developed the TracPhone(R) V7 two-way broadband satellite terminal.

Services Provided; E-mail, Multiple voice lines, Internet browsing, Instant messaging, (VPNs)

Data Speed; 2 Mbp.

Hardware Costs; V7 hardware costs $32,995 including voice. Cheaper options do exist like the KVH V3

Service Costs ; data will run more starting at $995

Harware providers; KVH, SeaTel,

Coverage; KVH Trackphone Map

Skymate Email Service


Skymate is a “store and forward system” and charges by character. In addition to text only skymate offers the ability to send faxes and even voicemail, Weather downloads are also a benefit. The outgoing message is read by computerized voice and delivered to a phone number. Skymate is not GMDSS capable. The antenna is a 38 inch whip.

Services Provided; E mail

Hardware Costs; For $1,200 you get silver box e mail system, which connects to your computer. and VHF style antenna.

Service Costs ; Pricing is per character transmitted, ranging from a $18/month plan for 8,000 characters sent and received, to $70/month for 50,000 characters.

Coverage; Skymate map showing large coverage but not Poles or lower South Africa


Text Messaging, Distress and Tracking



Globalstar has been around for a while, but have had problems with their satellites over the past few years. However for the future Globalstar has funding which will help it launch new satellites to get them back in the game. Press release from Globalstar. The French government is behind this and with Thales Alenia space providing the satellites

In the meantime Globalstars Spot satellite messenger is making inroads in the tracking field. Spot is not a voice satellite but a tracking device. The advantage of the Spot messenger is that friends can follow your adventures online with your position plotted on Google earth.

Spot inc is a subsidiary of Globalstar. Spot personal tracker is a more than a tracker it allows messages other than distress to be sent. Spot uses the simplex side of the Globalstar network so may not be influenced by the poor duplex Globalstar coverage of late. See for more on that. For more on SPOT and Globalstar and look for SPOT.

Services Provided; Text messaging, Rescue and GPS tracking.

Hardware Costs; The cost is $150 for the device

Service Costs ; $99/year subscription.

Coverage; Similar to Skymate, most of the world buy not close to the poles or lower South Africa. Map here


Reading the Yachting World report on the ARC rally you got the impression that people were having problems with perfectly good equipment. The problem many encountered is installation or operating problems. This can be teething issues because this equipment has specific installation issues.

The lesson to be learnt is to get the equipment well before a big passage and make sure the installation is working and you can test the gear and get used to it before you depart on your big cruise.

Communications Resources

Authorities and Government organizations who govern all aspects of communications

The IMO splits communications into three zones;

  • Area A1 Within range of VHF coast stations with continuous DSC alerting available (about 20-30 miles)
  • Area A2 Beyond area Al, but within range of MF coastal stations with DSC alerting (about l00 miles)
  • Area A3 & Area A4 The remaining sea areas.

Sat Phone or SSB

When looking for offshore communications we have a choice between satellite devices and SSB. There is no one answer as each has its benefits and downsides which we list below.

The Atlantic Rally for Cruisers (ARC) for example had a survey conducted by Yachting World magazine where 69% of the participants used Iridium. Inmarsat was second at 33%. Next came SSB users at 54% while SSB with modem was 15%. Check Yachting World December 2012 for more. Many of these cruisers used a Iridium phone with SSB as a backup.

Sat communications benefits Easier setup No License Portability

Negatives Expense Reliant on broadcaster

SSB Benefits; Cheapest to use Requires not outside broadcaster Multiple receptions Cruiser nets

Negatives Technically challenging Need expensive installation Antenna and ground plane Some Propagation issues Need License

Communications Glossary

Azimuth Azimuth is the horizontal angle, an antenna can be rotated through (from N) to point at a satellite.

AIS Automatic Identification System

Analog: A transmission method that uses a variable and continuous voltage to represent the current state. Analog devices monitor movement, temperature, and sound and convert them into a continuous mechanical or electrical output that changes with the condition being monitored.

ATC: Ancillary terrestrial component; i.e., a ground station.

Bit: A bit, or binary object, refers to a digit in the binary numeral system. There are only two possible values: 0 or 1. Binary digits are almost always used as the basic unit for digital information storage and communication

Bit rate: In communications and computing, bit rate (also written as “bitrate”) or data rate refers to the number of bits transmitted or processed in a specific unit of time. Bit rate is usually measured in seconds and written as bps or bit/s, often with a metric prefix such as kilo (kbps) or mega (Mbps).

Baud A modem transmitting at 2,400bps is operating at 600 baud

Bandwidth For digital signals bandwidth is measured in bps. A bandwidth of 56Kbps can transmit at 56,000bps.

Byte: A byte is commonly used as a unit of storage measurement in computers, regardless of the type of data being stored.

Digital: The word “digital” can have many meanings, but as applied to communications, it often is used to describe a signal that was converted from an analog source—a voice, for example—by sampling the analog signal at a very high rate.

DSC Digital Selective Calling is the red button on your radio for sending distress signals

Earth station: This term describes the combination of antenna and receiver electronics used to receive a signal transmitted by a satellite. (See LES.)

Footprint The surface map of the satellites signal.

GEO: Geostationary orbit, and orbit directly above the equator that allows a satellite moving at the same speed as the Earth’s rotation to remain virtually fixed in relation to a point on the Earth’s surface. Geostationary and geosynchronous are terms used to describe an object or a satellite that is in a geostationary orbit. Global beam: A global beam is a signal coverage pattern used by the Inmarsat satellites that effectively covers one–third of the globe.

GMDSS: The Global Maritime Distress and Safety System is an international safety system that includes requirements for types of equipment and communications protocols used to enhance maritime safety and rescue.

Inmarsat and GMDSS: Satellite systems operated by Inmarsat are an important part of the GMDSS. Four Inmarsat networks participate in the GMDSS systems: Inmarsat-A, -B, -C, and F77 netwrosk provide for communication between ships and shore, plus telephone, telex, and high–speed data services to and from rescue coordination centers. The F77 system must be used with Inmarsat-C to meet GMDSS data requirements. Inmarsat-C equipment provides email, messaging, and a data link between ships and shore, plus the option of sending preformatted distress messages to a rescue coordination center.

ISDN: ISDN (Integrated services digital network) is a standard for the integrated transmission of voice, video, and data.

IMO International Maritime Organization

LES: A land Earth station (Inmarsat) is an Earth station that provides a link between the satellites and the ground-based communications network. LESs are sometimes referred to as coast Earth stations, and they are the satellite equivalent of the HF or VHF coast stations. Today, there is no need for an Earth station to be on the coast, so “land Earth station” is probably a more accurate description of these stations.

MPDS: Mobile packet data service (Inmarsat). When you are connected to a network, it appears that information is being continuously sent in both directions.

MSS: Mobile satellite service.

MARPA Mini Automatic radar Plotting Aid

MMSI Maritime Mobile Service Identity

SIM card: A SIM (subscriber information module) card is a programmable card inserted into a phone to store a subscriber’s personal information and settings.

SMS Short message service aka text messaging.

SAR Search and Rescue Organizations

Transponder: A combination receiver, frequently converter, and transmitter installed on board a communications satellite.

Uplink: This refers to the Earth station used to transmit signals to a satellite.



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