Guide to Internet onboard

Guide to internet onboard outlines all the facts relating to getting fast and reliable internet access on board.

Whether you want internet onboard for pleasure or business use, the desire for the highest speed and reliability remains the same. There should be no reason to compromise on marine internet access when travelling around the Australian coast. This guide to internet onboard will step you through the do’s, dont’s and myths relating to getting and maintaining a reliable and fast internet connection on your boat.

Antennas for internet onboard

Possibly the most discussed and controversial topic is related to antenna choice and location.  They must be suited to the marine environment and mounted such as to not obstruct the operation of the boat at anytime. On a sailing boat, a good location is often on the rear bimini frame on either side of the boat or on the spreaders. Mounting on the spreaders can become a fouling issue with sails if not placed in the correct location.  On a power boat, antenna location is best on the top of a radar arch or fly bridge superstructure.  This can be the side of the radar arch or flybridge superstructure also.  Keeping them away from the radar is also required.

I mention antennas rather than just antenna because with many new modems they have the capability to utilise 2 antennas for increased speeds, bandwidth and redundancy. When operating closer to shore where visibility of more than one cellular tower is possible, having two antennas provides you the best possible speeds. When further afield and only a single cellular tower may be seen than the modem will be operating off a single antenna.

Coax Cabling

Following closely behind antenna choice and location in importance is antenna cable. You *must* ensure you use the highest quality coax cable for the connection from the antennas to the modem.   Keeping the coax cable runs as short as possible is also going to help. Locating the modem below decks as close as possible to where the coax comes through the deck is often a good option.

Why a Cel-Fi isn’t an option

The Cel-Fi units have been many peoples go to for a while now and while they still have a place their application focus has been primarily on boosting the available signal for making and receiving voice calls. It is recommended that these units be locked to 3G to ensure a signal is almost always available. They are also locked to a certain carrier and will only boost a single frequency at once (Phones and modems will often move around to different frequencies while operating to achieve a better signal quality). Locking the Cel-Fi to 3G is to the detriment of your internet speed, almost to the point of being unusable. If you chose to use a 4G modem through a Cel-Fi device you would find that you would not be able to achieve the speed desired. The Cel-Fi devices still require your mobile phone to be put in hotspot mode to share its internet connection as well, so this also adds to the poor performance. Essentially the Cel-Fi becomes a bottleneck for the 4G modem and as such we do not recommend using a Cel-Fi onboard if you want fast and long range internet.

Modem Choice

There are 3 must haves when choosing a suitable modem for your boat. 

  • Must have an external antenna option, the built in stubby antennas for the cellular connection just won’t work.
  • The modem must not consume much power and ideally have at least a direct 12 DC connection
  • The modem must support Band 28 which means the modem can operate on the 700Mhz frequency.  Since this is the lowest frequency currently available in the cellular network its propagation over water is the greatest and Telstra have made a point of provisioning this band on coastal towers around the country to assist with getting coverage further out to sea.  

Modem Features required for onboard use

In most instances, you will be wanting to connect to the internet using your devices Wi-Fi connection. In this regard, almost all modem/routers include Wi-Fi and have similar configuration options as your home Wi-Fi. At PicoSense we are happy to pre-configure modems and Wi-Fi networks prior to shipping so you don’t have to worry about this.

Depending on your boat type/size you may wish to add a Wi-Fi antenna to increase range, however in most cases the stubby antennas that is supplied with the unit is more than sufficient to provide Wi-Fi around an average sized boat (even on the fly bridge).  Some steel vessels will need to utilise external Wi-Fi antennas to ensure coverage around the boat.

Most modems include at least 1 wired LAN connection. This is handy for devices which don’t have Wi-Fi and require internet access.  I need to mention here also that tethering to your phone for internet access just won’t work reliably and will utilise a lot of battery power.

Choice of Telco / Carrier

Simply put, if you are in Australia, Telstra is your only reliable option for marine internet access. The kit we recommend works on the 4Gx/4G/3G bands and can switch between them. Telstra have excellent coverage around Australia in at least one of these bands. 5G is not going to be an option in the marine environment. Due to the way it works, propagation from the 5G tower is no more than a few hundred meters and requires multiple towers to achieve the speeds advertised. This is just not viable on the water.

Benefits of Internet onboard

In a lot of cases, if you have good quality antennas and are operating in and around a coastal port area you will have much faster access to the internet than a typical home ADSL or NBN connection.   Many people are now choosing to operate their business from their boat and this is entirely possible. Having an “always on” internet connection is handy for quick weather updates, BoM radar checking, not to mention being able to stream Netflix and stay in contact with family and friends in this connected world we all now live in.


This guide to internet onboard should assist you with selecting what hardware is required. Don’t let manufacturers confuse you with terms and lingo that they know most will not understand. Speak to us at PicoSense about what you want to achieve and we will come up with a solution to fit your budget and ensure that you fully understand all aspects of the technology and hardware. Check out our Internet Access Kit which includes everything you need to get “connected”. If you have a tighter budget and would like to discuss a scaled down internet kit, please get in touch with us as we can assemble a kit just for your boat.