WiFi Internet access on board

I’ve finally got our Internet access working the way I’ve always wanted. Now, whenever we arrive at a new destination, we can flip a single switch on our main panel, sniff out a nearby WiFi network and get online.

In a marina finding a WiFi network to connect to is straight-forward. When at anchor, it means searching for a decent WiFi signal from a coffee shop followed by a trip to buy an espresso or two, and leaving with their network password in our pocket.


Unlike much simpler solutions which can be plugged directly into a PC’s USB port, we have a large, permanently mounted high gain antenna which is capable of connecting to networks miles away. Once connected, our ship’s WiFi router allows all our devices (laptops, phones, iPads) to share the same Internet connection without having to re-enter user names and passwords.

Today, our neighbours have been complaining about the poor quality of the WiFi provided at the marina, yet we’ve had a reliable connection all day and have even been able to stream video.

This setup is the result of a couple of years of trial-and-error using a variety of hardware, made all the more difficult as everything has had to be restricted to 12 volts.

In this article I’ll give a brief overview of how it all works. I hope it proves useful to others who’d like to set up a similar installation in their boat or camper van.

A list of parts:

A similar all-in-one ‘Pro’ solution from a commercial marine vendor can be expensive, but if you buy the parts individually and are willing to spend a little time setting it up, then you’ll be left with change from £200:

  1. Ubiquiti Bullet M2
  2. 8dBi Omni-directional antenna
  3. UV resistant CAT5 ethernet cable
  4. 12v power over ethernet (POE) injector (to power the Bullet)
  5. USB powered WiFi router
  6. 12v to USB power adaptor (to power the WiFi router)

The Bullet is the key component in the system. It attaches directly to the high gain antenna and contains all the jiggery-pokery-magic that sniffs out WiFi networks for you. I bought the Titanium model (actually made from aluminium) as it looks much more robust and weather proof than its only slightly cheaper plastic counterpart. I chose an 8dBi antenna, as higher gain means a narrower beam angle that might miss a WiFi base station. It works well, and given clear line of sight has a more than adequate working range of over 5 miles. I found the guys at broadband buyer really helpful when I phoned for advice on this, and they helped to select a model that was more suitable for marine use, and very reasonably priced too.

You’ll need a short patch cable too. I decided to make my own and bought some RJ45 connectors and a crimping tool from eBay (it’s possible to learn how to do just about anything on YouTube). This also meant that I could terminate cables where I wanted to rather than having untidy coils of cable hidden behind panels around the boat. The cable tester proved invaluable as the first few leads I made had faults in them.


The trickiest item to find was a decent antenna bracket; they were either ugly, poor quality or laughably expensive. In the end, I had one fabricated from stainless steel specifically for the job – it looks great and only cost €20.00.

Putting it all together:

I’d spoken with a few vendors of all-in-one WiFi solutions at the London boat show, and the general opinion was that the ‘sweet spot’ for a WiFi antenna is about 3m above the water line. We already have an Navtex antenna mounted on the pushpit, so I just added the WiFi antenna to the same pole and ran the CAT5 cable from there inside the boat.


In the  closeup image, you can see the bracket I had made, and the nice weather proof fixings on the Bullet Titanium model. The only cable that runs to the Bullet is the CAT5 ethernet cable; the POE injector sends it power up a pair of otherwise unused wires in this cable.

At the other end of the CAT5 cable, the remaining components are attached to a plywood board:


Power from the switch panel (1) is supplied to the POE injector (2) and the USB power adaptor (3), which in turn powers the TP-Link WiFi router (6).

The CAT5 cable from the Bullet plugs into the POE socket of the injector (4) and 12 volts is sent to power it up. The network signal from the bullet is sent back down using different wires in the same CAT5 cable and relayed via the patch cable (5) to the TP-Link WiFi router (6).

The TP-Link WiFi router creates our ship’s WiFi network (to which we connect all our devices with a single password) and it forwards all requests for web pages to the Bullet.

The plywood board is backed with heavy duty Velcro which holds it snugly at the back of a cabinet by the chart table. The blue monkey-fist knot allows the board to be easily pulled out for maintenance.


Network configuration:

Wiring the components together is relatively simple. Configuring the networking can be quite tricky and I suggest that you get this all working on a bench before even thinking about installation. If you have some experience configuring networks, then you’ll be fine – if not, it might be worth buying a friend who has experience a couple of beers.

As far as I’m concerned, the trick to configuring everything is to be methodical and take small steps. Start with the Bullet and no WiFi router. To do this replace the patch cable shown above with a cable connecting the LAN side of the POE injector directly to your laptop or PC. Then follow the configuration instructions in the Bullet’s user guide. Set it’s network mode to ‘Router’ and enter the I.P. settings you want it to use.

Once you’re in a position where you can connect to a remote WiFi network using the Bullet, it’s time to start thinking about setting up your own local WiFi network for your devices to connect to. Again, do this with the Bullet turned off so that you can focus on the WiFi router. Importantly, you should make sure that the WiFi router will use a different subnet address from the Bullet. So, for example, if the Bullet is configured to use 192.168.1.X, then the WiFi router must be configured to use something like 192.168.2.X. Once this is working as you’d like, use the patch cable to connect the Bullet to the WiFi router and you’re done.

You should now be able to connect to the Bullet’s configuration pages via your local WiFi network and search for remote WiFi networks:


Sort the networks by signal to noise ratio.  Counterintuitively the best signal will be the one with the lowest value; in this case, the Vodafone network shown at the top of the list. Select this network and click the button to make the Bullet connect to it.

You should now be able to connect any number of devices on board to your local WiFi network, and they will all have internet access.



Two things to do with string

We couldn’t have wished for better weather over the past few days, and it’s been great relaxing here in Whitby, it’s a lovely town. Among other things, I’ve kept myself amused with a couple of minor jobs on the boat that have involved tying some quite intricate knots.

The first is called a turk’s head. It’s primarily a decorative knot and doesn’t have any real use apart from, when tied to a steering wheel, acting as a center mark that can be felt when the wheel passes through your hands.

Until today we had a plastic pull tie on the wheel, but now thanks to a length of old kite line and a little patience we’ve got a yellow turk’s head marking center:


The second job was to make up an anchor snubber. Without a snubber an anchor chain lies over a bow roller and is typically retained by the windlass. The forces employed to hold the boat in position when at anchor are therefore directly applied to these essential and expensive parts of the boat. A snubber’s job is to take this load and transfer it instead to a cleat, which is much more capable of handling such high loads.  A snubber simply consists of a hook that is attached to the chain and a mooring line from the hook that can be attached to a cleat.

We have two very heavy duty cleats either side of the bow roller so it seemed sensible to use them both. To do this I made up a snubber with a hook in the center of a length of mooring line, held fast using a seizing knot shown in the closeup here:


Navionics Vs SeaNav: Comparing navigation apps for iPad

Although we have some great navigation equipment on board, I wanted to get something that we could use while away from the boat to draw up passage plans. To this end I fired up the iPad and tried out two of the better looking marine navigation applications that claimed to support UK waters: the well established Navionics UK & Holland and the significantly cheaper new kid on the block SeaNav UK.

I’ve used Navionics software before and am not their greatest fan. I’ve had the iPhone version of this app for a while now and find that I continuously need to hunt through the poorly thought out menus to find anything other than its most basic features. On the other hand, the charts they use are excellent. In fact the exact same data is used in our on board Raymarine plotter so the charts in the iPad appear exactly as they do on the boat. As good as these charts are though, I’ve now paid for them three times – once for the on board systems, once for my iPhone, and now once more for the iPad. Navionic’s marketing strategy means that their charts are expensive.

When first using the SeaNav software, it instantly has a much better feel than Navionics. Menus are more easily accessible and the whole user experience just seems to be that little less contrived. Ultimately though, a navigation app is only as good as the chart data it contains, and in this area SeaNav was pretty poor in comparison.

Let me show you an example of how these apps stacked up against each other. One of the places we may stop this summer is Scarborough on the East coast of Yorkshire. Using the SeaNav app I zoomed in to take a closer look at Scarborough harbour and this is what I found (click the images to enlarge):


As you can see, the location of the cricket club is pretty clear, and I can find my way to Marks & Spencer with no problem, but where’s the harbour?

This is the same area on the Navionics app:


Now the position of the harbour is obvious, and the colours used for the depth contours have a better contrast and are much easier to see. I don’t play golf so I’m not too bothered by the disappearance of the golf club.

Importantly, SeaNav seems to have a problem where objects of interest become obliterated as it performs its vector rendering – in this case a whole harbour has disappeared!

If we zoom in a bit, then the harbour reappears:


Great, now we know where to go if we need shelter. But where are the pontoons, and where should we head to if the harbour master gives us instructions to moor agains the North Wharf?

Lets see what Navionics makes of it:


Much better. Not only does the harbour appear where it should, but theres much more detail inside too.

For me, being a non-golfer and a very occasional visitor to Marks and Spencer, Navionics is the better choice. It renders the charts well and very quickly. As for SeaNav, well I’m not sure if I’d feel comfortable with an app that can hide an entire harbour. What about wrecks or sand banks? Might it hide these too? I’ve not noticed this happening but given what I’ve demonstrated, I’m not confident that it wouldn’t happen. OK, I’m only looking to use this for initial planning, but I still feel more comfortable doing this with the correct data to hand.

Other things that I prefer in Navionics are its ability to cache large areas of charts very quickly on my iPad, SeaNav was not as adept at this and seemed to take much longer to download small areas of data. Navionics also provide better tide data by default; with SeaNav a separate app download is required if you want to see anything more than the next 24hrs of tides.

SeaNav is priced very attractively: £9.99 for an app that will run on both your iPhone and iPad. Navionics will charge you £57.48 for the privilege of using their software on both your devices (£37.99 for the iPad and £19.49 for the iPhone).

The SeaNav application is still only on version 1.11 so hopefully, with time, they’ll address the problems highlighted above. If they can provide better detailed charts and still undercut Navionic’s expensive pricing model, then I’m sure this app with its fresher user interface could be a real contender.