Offshore Internet: Starlink, VSAT, Iridium, OneWeb and 4G Compared for Vessels
Connected sailing is no longer a luxury — it’s an operational necessity for professional fleets and a basic expectation for demanding recreational sailors. But offshore connectivity options are varied and confusing. This guide analyses all available technologies in 2025 so you can make an informed decision.
The Five Main Technologies
1. Starlink Maritime (LEO — SpaceX)
The most recent and disruptive entrant to the marine market. Uses Low Earth Orbit (LEO) satellites, delivering latency that would have been unthinkable five years ago for satellite connections.
Strengths:
- Latency of 20-60 ms (comparable to a fibre connection on land)
- Speeds of high speed
- Global coverage without roaming
- Relatively accessible pricing for marine use
- More compact hardware than VSAT
Weaknesses:
- Expensive hardware ()
- Relatively new service (less track record than VSAT)
- Some plans have priority data limits
2. VSAT (Very Small Aperture Terminal — GEO)
The gold standard of the marine sector for decades. Uses geostationary (GEO) satellites at 36,000 km altitude. Main providers: KVH Industries (TracVision), Intellian, Cobham SATCOM.
Strengths:
- High reliability and technological maturity
- Guaranteed dedicated bandwidth (enterprise plans)
- Highly experienced technical support
- Ideal for large vessels with critical needs
Weaknesses:
- High latency: 600-800 ms — unusable for smooth video calls
- Large, heavy and very expensive hardware (enquire-18,000)
- Expensive subscriptions: enquire-4,500/month for competitive bandwidths
- Requires motorised antenna (more failure points)
3. Iridium (LEO — voice and slow data)
Original low-orbit satellite system with complete polar coverage. Widely used for expedition navigation and emergency communications.
Strengths:
- Complete polar coverage (unique in its class)
- Very reliable for emergency communications
- Portable devices available (Iridium GO!, satellite phones)
- Low power consumption
Weaknesses:
- Very low data speeds: very limited speed (standard Iridium), very limited speed (Iridium Certus)
- Not suitable for general web browsing or streaming
- High per-minute/MB cost on basic plans
4. OneWeb (LEO — Eutelsat)
Direct Starlink competitor in the LEO segment, focused on professional and specific geographic markets.
Strengths:
- Speeds similar to Starlink (50-195 Mbps)
- Low latency (30-70 ms)
- Focused on professional and marine sectors
Weaknesses:
- Network still expanding, ocean coverage more limited than Starlink as of 2025
- Less marine market penetration than Starlink
- Higher price than Starlink for similar specifications
5. Marine 4G/LTE
Covered in detail in our Starlink vs. 4G comparison, but in summary: excellent coastally, useless offshore.
Full Comparison Table
| Technology | Speed | Latency | Ocean coverage | Hardware | Monthly cost |
|---|---|---|---|---|---|
| Starlink Maritime | high speed | low latency | ✅ Global | enquire–900 | |
| VSAT GEO | 5–50 Mbps | 600–800 ms | ✅ Global | enquire–18,000 | enquire–4,500 |
| Iridium Certus | very limited speed | 100–200 ms | ✅ Global + polar | enquire–7,000 | enquire–720 |
| Iridium standard | very limited speed | 200 ms | ✅ Global + polar | enquire–1,800 | enquire–270 |
| OneWeb | high speed | low latency | ⚠️ Partial | enquire–1,080 | |
| Marine 4G | 30–150 Mbps | 30–80 ms | ❌ Coastal only | enquire–700 | enquire–180 |
Optimal Combination by Profile
Recreational ocean sailor (yacht, sailboat)
Recommendation: Starlink Maritime Standard + Iridium GO! for emergency
- Starlink covers 99% of needs en route
- Iridium GO! provides emergency communications and polar coverage if needed
Superyacht (30m+, multiple users)
Recommendation: Starlink Maritime Priority + 4G router in port
- Sufficient capacity for 20+ simultaneous devices
- 4G in port reduces consumption of Starlink priority data
Professional fishing fleet
Recommendation: Starlink Maritime + dedicated VMS system
- Starlink for communications and weather routing
- Dedicated VMS (regulatory requirement) can integrate with the Starlink network
Commercial / critical offshore vessel
Recommendation: VSAT Enterprise + Starlink as backup (or hybrid solution)
- For critical operations where guaranteed reliability matters more than price
- Starlink as backup channel and for crew welfare
Polar expedition
Recommendation: Iridium Certus + Starlink (where coverage available)
- Iridium for basic communications in extreme polar regions
- Starlink for the rest of the voyage
Why Starlink is Winning the Marine Market
In 2023-2025, Starlink has gained significant marine market share for three main reasons:
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Latency changes everything: with VSAT, video calls have a 600-800ms delay that makes them almost unusable. With Starlink, they’re indistinguishable from a shore-based call.
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Price per megabit: Starlink offers 10-20 times more speed than VSAT at the same price, or the same speed at a fraction of the cost.
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Installation: a Starlink antenna weighs 3.5 kg and is installed in half a day. A VSAT antenna with motorised stabilisation system can take a week’s work and weigh 80 kg.
Frequently Asked Questions
Is VSAT still relevant in 2025?
For large commercial vessels, expedition ships and critical applications where guaranteed reliability matters more than speed, VSAT remains relevant. For yachts, sailboats and fishing fleets, Starlink has outperformed VSAT on almost every metric at better cost.
Can I use Iridium for offshore weather routing?
Yes, but with limitations. Standard Iridium speed (very limited speed) is sufficient for downloading low-resolution GRIB files and sending/receiving messages. For detailed meteorology, high-resolution GFS models or advanced routing, you need a faster connection like Starlink or Iridium Certus.
What system is best for an Atlantic crossing from the UK or Europe?
Starlink Maritime is the most balanced option for an Atlantic crossing: complete coverage from Europe to the Caribbean, speeds suitable for remote work and video calls, and reasonable pricing. Complementing with an Iridium GO! for emergencies is strongly recommended.
Will OneWeb become competitive with Starlink for marine use?
OneWeb has potential, but in 2025 Starlink has a significant advantage in ocean coverage, pricing and marine support ecosystem. OneWeb is gaining ground in specific markets (Arctic, some Pacific zones) where its coverage is better than Starlink.
Need help deciding which system suits your vessel and navigation pattern? Contact us for a free consultation.