Sunday, 12 April 2015

View Open CPN On The iPad

Open CPN is a very popular navigation program for cruising sailors. Now, with the advent of accurate charts derived from Google Earth satellite images, it plays a very important role for us in tropical areas.

Like many boats, Crystal Blues has the navigation PC installed below decks at the nav station, locked down in a safe and (hopefully) dry location.

However we really want to see those Google Earth charts when we are up on deck, moving around in the cockpit and at the wheel.

The iPad is the perfect tool for this, portable, stable and with good battery life - but Open CPN doesn't run on the iPad.

The iPad does have WiFi capability, so in theory at least we could connect it to our PC down below at the navigation station, which is exactly what we do.

We use Splashtop Streamer, a free shareware application, to stream the PC screen directly to our iPad. This allows us to see the PC screen from anywhere on deck (in fact anywhere on the boat), and provides basic mouse and keyboard functions to control the PC as well.

So, I can stand at the wheel and see the display from Open CPN, or from our Transas Navigator ECN  package, in real time.  I can review my Sailmail GRIB files as well, without having to "go below".  So how does this work?


You can download Splashtop Personal for the iPad from the Apple Store, then download the Splashtop streaming application for PC from the Splashtop site here.   It is a neat system - the streaming application sits in the background on the PC, until it receives a request for connection from the iPad.  At that point the iPad can take control, so long as the iPad user has the correct PC logon password.

The PC screen is then broadcast ("streamed") to the iPad, with a pop-up keyboard and mouse functionality available on the pad.

Conventional Chart Data - Oops
The WiFi link can mean that it's a little slow to update, but most screen changes are dealt with in a few seconds and the streamer package is quite stable once connected.

The streaming software is also available for Mac and Linux users.

Our wifi onboard is managed by a small (12volt powered) D.Link router, though I understand that Splashtop will also work fine on a "direct to PC" peer to peer wifi link.

Splashtop can get fussy if you have too many iPads onboard, but keep it simple and it works.

The end result is a portable PC viewer on the iPad, that puts those Google Earth KAP images right where we want them all the time.


Google Earth KAP Chart
I'll sign off with the two images (at left and above) from our travels a couple of days back, that sum up the advantages of Google Earth charts in tropical areas.

Go figure ....... the conventional chart data puts me on land, but Google Earth data shows that I'm navigating safely.

Click on the images to enlarge for more detail.

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