Internet Onboard: Installing a 4G/5G Router and Starlink

A yacht setting off on a week-long tour of the Bodrum coves can no longer rely on a phone signal the moment it leaves the marina. Onboard internet has become critical infrastructure for far more than communication — weather routing, passage planning, remote monitoring systems and guest comfort all depend on it. This guide covers what actually works in the field, from choosing a 4G/5G router to installing Starlink, sizing the power draw and designing the network.

Cellular or satellite at sea?

Onboard internet relies on two core technologies, usually deployed together:

• Cellular (4G/5G) is fast and inexpensive close to shore. It performs well in marinas, coves and along the coastline out to a few nautical miles, but coverage depends entirely on the carrier and coastal terrain.
• Satellite internet (Starlink and similar) takes over as you move away from shore and offshore. It delivers low-latency, relatively high-speed connectivity independent of geographic obstacles.

In a region cruised cove by cove like the Bodrum peninsula, the most practical solution is usually to install both: a network that uses cheap 4G/5G near marinas and the coast, and Starlink for open-water crossings.

Choosing a 4G/5G router and antenna

Your phone's hotspot may be fine for short-term use, but continuous use calls for a dedicated marine-grade router. Household routers aren't built for dust, moisture or vibration, and most are locked to a single carrier. Points to check when choosing:

1. Dual-SIM or multi-carrier support. Coverage can vary between carriers along the Bodrum coastline; a dual-SIM router automatically switches away from a weak signal.
2. External antenna connection. A built-in antenna is weak inside a metal-hulled boat's wheelhouse. An external 4G/5G antenna mounted on the mast top or near the radar arch noticeably improves signal strength.
3. PoE or a separate power input. If the cable run between antenna and router is long, Power over Ethernet simplifies the wiring.
4. IP rating. Antenna units mounted on a mast top or open deck should be rated at least IP65.
5. Management software. Being able to check signal strength, switch carriers and monitor data use remotely makes life easier, especially on a boat left unattended.

Coverage from different carriers can vary noticeably between coves on the Bodrum peninsula, so a dual-SIM router delivers far more reliable results than sticking with a single carrier.

Starlink Maritime: installation and power needs

Starlink's marine-rated terminal (Flat High Performance or Maritime model) is mounted on a motion- and vibration-resistant base on a yacht's flybridge or radar mast. Points to watch during installation:

• Field of view. The dish should sit as far as possible from obstructions such as masts, funnels or the radar arch, with a wide, unobstructed view of the sky.
• Power draw. The terminal typically draws 50–150 W in operation, equivalent to roughly 4–12 A on a 12 V system. This continuous load must be factored into your daily energy consumption calculation.
• AC-powered units. Standard Starlink kits usually come with a 100–240 V AC power supply; on a boat this needs to be fed from an inverter or a generator. DC-only marine-grade power adapters also exist, making it easier to feed the terminal directly from the battery bank.
• Mounting. The base must be secured against vibration and wave impact using the manufacturer's recommended mounting kit and stainless fasteners.
• Cable entry. The cable running from the terminal into the cabin should pass through a watertight fitting or deck gland, routed so it doesn't allow water to pool on deck.

A Starlink terminal keeps the connection alive underway, which is especially valuable at anchor outside a marina or crossing between islands. But hardware and subscription costs are noticeably higher than a 4G/5G router, which is why most yachts install both as complementary, redundant systems.

Wiring, power supply and redundancy

The router and Starlink terminal need to be fused and wired at the correct gauge for voltage drop, just like any other electronic system on board.

Having communication systems drop out along with the main battery switch is a safety risk; for emergency communication it's good practice to feed the router from a separate, easily accessible fuse, the same way VHF and navigation equipment are wired. The general approach to cable gauge and voltage-drop calculation applies to every circuit in marine wiring; see our electrical services for more detail.

On boats that want to power AC-fed devices like the Starlink terminal directly from the battery bank, an isolated DC-DC converter such as Victron Energy's Orion-Tr Smart series provides clean, stable voltage — which also extends the life of sensitive electronics.

Network architecture: Wi-Fi distribution and security

A single router's Wi-Fi signal may not reach the salon, cabins and flybridge with equal strength on a steel- or aluminium-hulled motor yacht. On mid-size and larger boats, the recommended layout is:

• The router handles the internet inputs (4G/5G and/or Starlink) and acts as the primary gateway.
• Several Wi-Fi access points, distributed over an Ethernet backbone, give even coverage throughout the boat.
• The guest network should be separated from the network carrying boat automation and monitoring, so that a problem on a guest device doesn't affect your remote monitoring system or the NMEA 2000 gateway.
• Default passwords on the router's admin panel should be changed, and firmware kept up to date.

Pre-installation checklist

• Have you checked the coverage map for the carriers most used along the coastline?
• Does the router support dual-SIM or multi-carrier operation?
• Has the mounting point and cable run for the external antenna been decided?
• Is there an unobstructed sky view for the Starlink terminal?
• Has the power draw been added to the overall energy budget?
• Does each device have its own fuse and the correct cable gauge?
• Are the guest and automation networks kept separate?

Work with Aslan Yacht on your onboard internet

From our workshop in Turgutreis to marinas across the Bodrum peninsula, we design 4G/5G router, external antenna and Starlink terminal installations to work cleanly with your existing electrical and electronic systems. From the power budget to the wiring, and from network architecture to our electronics and navigation services, we're with you throughout — get in touch to plan your installation.