Adding more to your maps with marine charts

I haven't posted a lot over the past year about what I've been working on, but I've spent a lot of time building a web application that tracks ships around the world using positions relayed by satellite. I'll post more on the project soon, but for now I just want to share one of the ways that we're improving the usefulness of the maps as part of this project.

At their heart, the maps in the application are based on OpenStreetMap data and satellite imagery from MapBox, but when your clients are mostly looking at their vessels in seas and oceans around the world, traditional web mapping data doesn't really give enough context. Marine charts can fill in those big blue gaps and aid with using the map.

Map of the Isle of Man with Marine Charts overlaid
Map of the Isle of Man with Marine Charts overlaid
Map data © OpenStreetMap & MapBox, Marine charts © Crown Copyright, 2013. All Rights reserved. Licence no. EMS-EK001. Not to be used for navigation.

MarineFIND - with whom I've been working with to deliver this project - provide marine charts in various formats, including as a tile map service or web map service for clients who are looking to add charts to their own applications. The charts are made available either individually in their original form, or joined together to form an almost seamless detailed chart of the world. The combined chart layer cuts the landmass out, leaving them transparent, allowing the layer to be used on top of satellite imagery or other maps.

Map label overlay

Satellite labelling solution

Combining two raster datasets - the merged charts and the OpenStreetMap maps - into a single map causes some issues when it comes to labelling. Especially around coastal areas, labels from OpenStreetMap may be obscured when overlaying the marine charts.

This can be overcome to some extent by showing the charts as semi-opaque (see left), but for the satellite data we found another way of doing it (see right). Starting with an unlabelled satellite imagery layer from MapBox (which can be coloured to your liking), we then add the marine charts, and finally a separate MapBox Streets layer showing just line data and labels, meaning that any overlapping labels will be shown on top of the charts as expected.

If you want to find out more about using charts for your own applications, please feel free to get in touch, or contact MarineFIND for information about licensing.

Trying out the Nomad ChargeKey

If you follow me on Instagram (@dan_karran) you may have seen me post a month or so ago about the Nomad ChargeKey that I was given to try out.

The ChargeKey is a little USB key that you can clip on to your keyring to use as an iPhone charger when you don't have your Apple-specific Lightning USB charging cable with you. There'a also an Android Micro USB equivalent. You still need a USB socket to plug the ChargeKey into, of course, but if you have one of those to hand then you can easily charge your phone back up to capacity.

A month down the road and I've used it occasionally, usually while sitting at my desk at work or when I've been at friends' places. It's been convenient to have the Nomad ChargeKey around, and I'd recommend it, but as someone who likes to take lots of photos with my iPhone and track my walks and runs with battery-intensive apps, I think the more important thing for me will be an external battery that I can keep in my bag to recharge whenever necessary, when I'm away from the computer.

The ChargeKey is available on Amazon in two flavours, one for Android and one for iPhone at a price of £16. Nomad also make creditcard shaped chargers, known as the ChargeCard, but my wallet is already stuffed to bursting point with old receipts and loyalty cards, so I didn't try that one out.

Kaart Çheerey - a Manx language map of the world

Kaart Çheerey - a Manx language map of the world
A Manx language map of the world -

The month of September has been renamed to Maptember this year because of the number of geographic conferences that are going on. With the thought of a month of maps ahead, I decided to make a new map: a Manx language map of the world.

The map - known as a kaart çheerey in Manx - displays continents, countries and oceans that have been documented on the Manx language Wikipedia and visualises them as a browsable map which can be accessed at

My great grandparents were some of the last native speakers of the Manx language, and the language lost its last native speaker in 1974. In an effort to re-introduce the language to the island, Manx has been taught in schools on the Isle of Man since at least the early 1990s. Some children on the island are brought up as native Manx speakers (in addition to English) at the only Manx language school, Bunscoill Ghaelgagh. Manx translations can often be seen on road signs and other official signage, and can be heard on radio broadcasts and at the annual Tynwald Day ceremony.

I learned a bit of Manx at school, though not much of it has stuck with me. Because of that, I struggled a little to find all the names I wanted from the Manx Wikipedia, and I ended up simply searching for each country and seeing what was returned as the top result (or near the top). Often the names resemble the English version - especially if read out in a bit of a Manx accent - so it was usually obvious which article referred to the country. For example, Germany becomes Yn Ghermaan, Finland becomes Finnlynn and Canada becomes Yn Chanadey. Some smaller island nations didn't appear to have articles about them, but that there was an article for most countries in the world still struck me as quite impressive, for a language that is spoken fluently by such a small number of people.

The cartography on could do with some tweaks still, but hopefully the map will be useful for anyone curious about this language from the heart of the British Isles. If you see any mistakes on the map, please let me know in the comments.

I'll likely be tweeting geographic things more often than usual this month @dankarran and may blog a little about the Society of Cartographers and FOSS4G conferences that I'll be attending as well.

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