Maritime
25 results
Maritime
25 results
Satellite Internet
Maritime Satellite Internet: GMDSS Safety Through Megabit VSAT
Terminals for every vessel class: Iridium GMDSS and voice for workboats, Fleet One and FleetBroadband for coastal craft, Certus for global crews, and Ku or Ka-band VSAT when the bridge and the crew both need bandwidth.
Who maritime satellite internet is for
A 65-foot longliner working the Gulf needs weather, a daily catch report and a way to call home. A crew-transfer vessel needs its charterer's tracking feed and email that does not stop at the 12-mile line. A tanker needs regulatory safety equipment, crew Wi-Fi and a link the operations office can rely on. These are three different budgets and three different terminals, and this page covers all of them.
Maritime equipment differs from land gear in three ways: it is built and certified for salt, vibration and constant motion; the antennas are either stabilised domes that track a geostationary satellite or omnidirectional L-band units that do not need to; and the category includes safety-of-life equipment, the Global Maritime Distress and Safety System, which no other page on this site carries.
Read the four tiers below, find your vessel, then use the comparison tables. Satmodo also supplies Starlink for business and maritime use at /buy/starlink; many vessels pair it with an L-band terminal from this page as the always-on backup.
Iridium GMDSS, safety and voice terminals
Lars Thrane systems for compliance and pole-to-pole voice, and the Certus voice terminal from Cobham SAILOR.
Fleet One and FleetBroadband terminals
Inmarsat L-band for coastal and offshore vessels.
Iridium Certus maritime terminals
Global, weather-resilient L-band with no moving parts.
Ku-band VSAT antennas
Stabilised Ku systems from 83 cm to 1 m, convertible to Ka.
Global Xpress and Fleet Xpress Ka-band antennas
65 cm and 1 m terminals for the Inmarsat Ka network.
How to choose a maritime satellite terminal
Four tiers, from safety-first to bandwidth-first.
1
Tier 1: Iridium safety and voice (Lars Thrane LT-3100 and LT-3100S)
The LT-3100S is an Iridium GMDSS terminal with Distress Alert, Safety Voice and Maritime Safety Information, MED and Wheelmark approved as an alternative to Inmarsat C on IMO vessels. The LT-3100 is the non-GMDSS version for voice, SMS, SBD data and vessel tracking. Both use a single cable to an antenna up to 500 m away and work pole to pole. This is not broadband; it is the equipment that keeps you legal and reachable.
2
Tier 2: Fleet One and FleetBroadband (Inmarsat L-band)
Fleet One is the smallest Inmarsat maritime service: voice plus standard IP up to 100 kbps on the SAILOR package, or up to 150 kbps on the Intellian unit, with 505 emergency calling straight to a rescue centre. FleetBroadband steps up through the SAILOR 150 (150 kbps, 4 voice lines), 250 (284 kbps, 6 voice lines) and 500 (432 kbps, 9 voice lines, 3-axis stabilised antenna). Email, weather, forms and voice for coastal and offshore vessels.
3
Tier 3: Iridium Certus (Thales, Cobham SAILOR, Blue Sky)
Certus terminals use a small omnidirectional antenna with no moving parts and cover the poles. The Thales VesseLINK 200 delivers 176 kbps each way and three voice channels; the full VesseLINK and the SAILOR 4300 run Certus 700 at up to 704 kbps down and 352 up with three voice lines; the SAILOR SC4000 is a Certus voice system; the Blue Sky Skylink 6100 is a low-power Certus 100 kit for telemetry and unmanned vessels. Weather-resilient and truly global.
4
Tier 4: Ku and Ka-band VSAT (SAILOR and Intellian)
Stabilised dishes from 65 cm to 1 m that move speeds from kilobits to megabits. Ku-band: SAILOR 800 (83 cm), SAILOR 900 (103 cm), Intellian v85NX (85 cm) and V100NX, all convertible to Ka. Ka-band Global Xpress and Fleet Xpress: SAILOR 60 GX and Intellian GX60NX (65 cm), SAILOR 100 GX and Intellian GX100 (1 m), with the GX60 rated up to 50 Mbps. Crew Wi-Fi, cloud operations, video.
Fleet One vs SAILOR 150, 250 and 500 FleetBroadband
The Inmarsat L-band ladder, from the satmodo.com product pages.
| SAILOR Fleet One | Intellian Fleet One | SAILOR 150 FB | SAILOR 250 FB | SAILOR 500 FB | |
|---|---|---|---|---|---|
| Standard IP | Up to 100 kbps | Up to 150 kbps | Up to 150 kbps | Up to 284 kbps | Up to 432 kbps |
| Streaming IP | Not offered | Not stated | Not stated | 8 to 128 kbps | 8 to 128 kbps; ISDN 64 kbps |
| Voice lines | 1 phone/fax port, 4 kbps voice | Simultaneous voice and data | 4 lines, built-in PBX | 6 lines, PBX for 16 handsets | 9 lines, PBX |
| Safety | Coastal or Global service | 505 emergency calling to an MRCC; MST ready | Not stated | Not stated | Not stated |
| Antenna | Small and light (weight not stated) | Lightweight, single RF cable | 3.9 kg | Under 30 cm, 5 kg | 3-axis stabilised (weight not stated) |
| Best for | Small craft, voice first | Small craft wanting 505 and Wi-Fi | Single user, email and weather | Small crews, more voice | Working vessels needing the most L-band throughput |
Sources: satmodo.com product pages for sailor-fleet-one, intellian-fleet-one, sailor-150-fleetbroadband, sailor-250-fleetbroadband, sailor-500-fleetbroadband. 'Not stated' means the figure is absent from the product page.
Thales VesseLINK 200 vs VesseLINK vs SAILOR 4300 on Iridium Certus
Three Certus terminals, from the satmodo.com pages and iridium.com.
| Thales VesseLINK 200 | Thales VesseLINK | Cobham SAILOR 4300 | |
|---|---|---|---|
| Certus tier | Certus 200 | Certus 700 | Certus 700 |
| Data | Up to 176 kbps transmit and receive | Up to 704 kbps down, 352 kbps up (tier rating) | Up to 704 kbps down, 352 kbps up (tier rating) |
| Voice | 3 dedicated channels | Up to 3 channels | Up to 3 lines |
| Antenna | Low-gain omni, no moving parts | 35.6 cm diameter, 22.9 cm high, 3.2 kg | Not stated |
| Terminal | Not stated | 30.5 x 22.9 x 7.6 cm, 3.4 kg | Bulkhead or 19-inch rackmount |
| Wi-Fi and devices | 802.11 b/g, up to 12 devices | 802.11 b/g, up to 12 devices | Multi-user IP and VPN |
| Safety | GMDSS-capable | Not stated | Not stated |
| Maintenance | Not stated | Not stated | No scheduled service interval for at least 10 years |
Sources: satmodo.com product pages for thales-vesselink-200-antenna, thales-vesselink, sailor-4300-l-band; iridium.com Certus 700 page for the tier speeds.
Maritime VSAT: choosing between Ku-band and Global Xpress
Ku-band systems (SAILOR 800 and 900, Intellian v85NX and V100NX) work with a wide choice of regional and global Ku networks and can be converted to Ka in about 10 minutes on the Intellian NX units. The SAILOR 800 uses an 83 cm reflector with a 6 W BUC (20 W optional); the SAILOR 900 uses a 103 cm reflector with 20 W and 8 W BUCs and dual-antenna failover that switches in 20 milliseconds. Fleet Xpress plans on the SAILOR 800 run from 1024 kbps down and 512 up to 8192 down and 4096 up.
Global Xpress and Fleet Xpress terminals are Ka-band and tied to the Inmarsat network: the SAILOR 60 GX and Intellian GX60NX use a 65 cm reflector with a 5 W BUC (10 W upgrade on the GX60NX), the SAILOR 100 GX and Intellian GX100 use 1 m dishes, and the Intellian GX60 is rated up to 50 Mbps. Fleet Xpress bundles the Ka link with FleetBroadband L-band as backup, so a SAILOR 500 or 250 already on board is not wasted. Larger dish means more margin in rain and more throughput; 65 cm suits smaller vessels and yachts, 1 m suits ships that need the link to hold in weather.
What you need alongside a maritime terminal
Installation on a vessel is a project; budget for these.
An airtime plan matched to the network: Iridium GMDSS or Certus, Fleet One Coastal or Global, FleetBroadband, Fleet Xpress or a Ku plan.
Cable runs from the antenna to the bridge. Lars Thrane systems accept up to 500 m on a single cable; VSAT systems ship with 1 m coax and need runs specified at survey.
Rack space and power below deck: VSAT antenna control units and GX modems are 1U 19-inch rackmount, AC powered; the SAILOR 4300 comes in bulkhead or rack form.
The LT-3140S Interface Unit if your GMDSS install needs SSAS alerts, alarm panels, printers, BAM or ECDIS integration.
A backup L-band link for any VSAT vessel; Fleet Xpress builds this in, otherwise pair a Certus or FleetBroadband unit.
Fitting out or refitting a vessel?
Tell us the vessel type, route and crew size. We will recommend the safety terminal, the broadband tier and the backup, and quote the install.
Keep reading
From the Satmodo help centre
Cobham SAILOR Fleet One User and Installation ManualInmarsat FleetOne Coastal Coverage MapLars Thrane LT-3100/LT-4100 SIP SetupCobham SAILOR 4300 L-Band Firmware Version 1.08Intellian GX60NX Maritime Global Xpress Terminal OverviewSAILOR 900 VIASAT KA Data SheetBlue Sky Network SkyLinkIridium Certus 700 Upgrade Brings the Fastest L-band Speeds to the IndustryFrequently asked questions
What is the best satellite internet for a boat?
It depends on vessel size and what the crew sends. Small craft that mostly need voice and weather do well with Fleet One or a Lars Thrane LT-3100. Offshore vessels with a crew wanting email and voice move to FleetBroadband or a Certus terminal such as the Thales VesseLINK. Ships needing megabits for operations and crew welfare install Ku or Ka-band VSAT, often with L-band as backup.
What is GMDSS and do I need it?
The Global Maritime Distress and Safety System is the international framework of distress alerting, safety voice and maritime safety information broadcasts that SOLAS vessels must carry. The Lars Thrane LT-3100S is an Iridium GMDSS terminal, MED and Wheelmark approved, offered as an alternative to Inmarsat C. Carriage rules depend on flag, tonnage and trade; we can walk you through them.
How fast is maritime satellite internet?
Fleet One reaches 100 to 150 kbps, FleetBroadband up to 432 kbps on the SAILOR 500, and Iridium Certus 700 terminals such as the VesseLINK and SAILOR 4300 up to 704 kbps down. VSAT is where it becomes megabits: the Intellian GX60 is rated up to 50 Mbps and Fleet Xpress plans on a SAILOR 800 go to 8192 kbps down and 4096 up.
Ku-band or Ka-band VSAT?
Ku-band antennas (SAILOR 800 and 900, Intellian v85NX and V100NX) work with many networks and convert to Ka later; Ka-band Global Xpress and Fleet Xpress terminals are tied to Inmarsat and bundle L-band backup. Ka offers higher throughput; heavy rain affects it more, which is why 1 m dishes are preferred for vessels that must hold the link in weather.
What is the difference between Fleet One and FleetBroadband?
Fleet One is Inmarsat's entry maritime service with voice and standard IP up to 100 kbps (150 kbps on the Intellian unit) for small vessels, with Coastal and Global plan options. FleetBroadband is the professional tier: 150, 284 or 432 kbps on the SAILOR 150, 250 and 500, with more voice lines, streaming IP and larger stabilised antennas.
Does Iridium Certus work at sea everywhere?
Yes. The Iridium constellation of 66 satellites covers the globe pole to pole including the deep oceans, and Certus antennas are omnidirectional with no moving parts, so a vessel rolling in a seaway stays connected. Inmarsat's geostationary satellites do not cover the polar regions.
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