Summer fog banks

It’s been a tricky few weeks working our way along the Portuguese west coast. There have been a few days with good sailing conditions and some wonderful destinations, but on the whole we’ve been motoring a lot more than we’d have liked, dodging gazillions of poorly marked lobster pots along the way.

We’ve grown to love our radar, and have relied on it to get us through the dense summer fog banks, made all the more interesting by the crazy fishing boats who don’t bother with automatic identification systems (AIS), and just motor around without a care in the world, not even sounding a horn to announce their presence.

In da fog

To help, we’ve made good use of MARPA (Mini Automatic Radar Plotting Aid) to monitor their whereabouts:

Radar tracking

The red triangles are dangerous targets which, once they’ve been manually identified, are automatically tracked by the radar which sounds an alarm if they get too close.

Here’s Helena adding targets while we both keep an eye out for anything we may have missed with the radar, like the lobster pot on our port side:

Look out

Even when we get close, and know that there’s a boat out there, it’s a relief when it is finally spotted and we know we’ve passed it safely. Can you see the fishing boat in this photo?

spotted a fishing boat in the fog
Well that’s my whinging done – in my next post I’ll be a bit more upbeat I promise and will describe some of the lovely places we’ve found along this stretch of coast.


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.