Which is the best UK outdoor map?

Walking mountains and coastlines has been a passion of mine for over 20 years. So has mapping, which I’ve done professionally in some form or other for about the same period. But it only occurred to me now to bring the two together in this post.

In Britain everybody associates outdoor maps with Ordnance Survey. Based on over 200 years of cartographic tradition, their brand is a household name and the gold standard by which other maps are judged. OS is so dominant that most people don’t even realise there are alternatives out there which, in some cases, may suit their needs better. First there is Harvey, a specialist mapmaker for walkers, cyclists and mountaineers. Harvey has been around for decades and is highly respected within their respective outdoor communities. I’ve used their maps particularly in mountainous areas such as Scotland. More recently I bought my first Splashmap, which is printed on novel waterproof fabric (more on that later). Splashmaps are made by a small start-up company who, to my knowledge, are the first to ride the wave of open data for the outdoor consumer sector.

So now that there are three serious map contenders in the British outdoors, how do they compare?

From left to right: OS Explorer, Harvey, Splashmap.

From left to right: OS Explorer, Harvey, Splashmap.

Paper vs digital

First I should clarify that I’m only reviewing paper maps here, not digital. Digital mapping certainly has its place, but I take it as a given that you will always take a paper map and compass at least as a back-up – your local mountain rescue or coastguard team will thank you for it.

There will always be a market for paper maps, and the recent hysteria about the “death” of paper maps is simply misguided. Besides many people do not seem to realise that papers maps are made from digital maps, not vice-versa. Far from killing off paper maps, digital mapping improves the way paper maps are made. With digital, you can customise maps or just print them on demand, making sure retailers don’t have to flog left-over stocks of outdated maps. Enough said.

The test terrain

I recently compared all three maps on a half-day trek across Dartmoor, my nearest national park. Dartmoor is renowned for its fickle weather and tricky navigation. Even though it’s mostly a featureless expanse of wilderness, rising barely above 600 metres, the terrain is easy to underestimate. Many people have got lost in bad weather, and over the years a few unlucky ones died of exposure. No wonder Dartmoor also serves as a military training ground. What better terrain to put these maps to the test?

View of northern Dartmoor.

View of northern Dartmoor.

First impressions: Cartography

OS maps come in two scales, Explorer (25K) and Landranger (50K). Both are targeted at a wide audience, for multiple uses. This inevitably makes their cartography a bit of a compromise. I’ve never been a great fan of the Landrangers – their scale is just that bit too small, and the colours a bit too boudoir for my liking. Explorer maps, on the other hand, are highly detailed, and the cartography manages to just about balance all this information with legibility – just. In very steep or multi-use terrain the detail can become overpowering, with too many features competing for attention. On the bleak plains of Dartmoor, however, OS Explorer works very well: there is lots of space for contours, streams, tracks, place names and other detail not to get in the way of each other.

Harvey maps are tailored towards the single pursuit of walking or cycling. Their pastel cartography is beautiful to look at, and tones down any features that are less relevant for outdoor pursuits (e.g. urban features or road classifications). The whole map is filled with pleasing natural hues, colour-coded for elevation, leaving no white spaces. No other map I know reproduces the lay of the land as clearly and effectively. This makes Harvey maps particularly useful in mountainous terrain but also on the high moors of Dartmoor it works very well. And with the 40K scale the whole national part fits on a single map sheet without losing important detail.

Splashmaps are the new kid on the block. Their cartography seems to prioritise the needs of off-road cyclists above everything else: bridleways look like they’ve been painted on with orange lipstick. Although not great in aesthetic terms, it must be quite good for blurry eyes after a death-defying downhill ride. Other than that, the Splashmap cartography is a bit reminiscent of continental-style mapping such as the French IGN or Swiss Topo. There’s no area shading except for woodland and water bodies, so at first sight the prominence of line features like contours, roads or tracks can be a bit overwhelming. This is accentuated by the linework being slightly thicker than normal, which isn’t very pretty. Like Harvey’s, the Splashmap is printed at a scale of 40K, so the whole of Dartmoor fits on one sheet.

Verdict: Harvey is the beauty, Splashmap the beast, and OS a bit of both.

Detail and completeness

Note I’m avoiding the term ‘accuracy’ here. A map is an abstract representation of the world and so will always require a degree of interpretation and prioritisation. These days positional accuracy is not really a concern anymore; what matters is completeness and fitness-for-purpose. OS and Harvey have their own data collection operations, so they are in complete control of the detail shown in their products. Aerial and ground surveys, however, are not something a young start-up company could ever hope to afford. Splashmaps therefore rely entirely on third party sources, so-called ‘open’ datasets. Freely downloadable from government or volunteer sites, these include OS OpenData, OpenStreetMap and local councils.

OS Explorer, thanks to its larger 25K scale, is by far the most detailed map on the market. On the bleak plains of Dartmoor, any detail is reassuring and so the Explorer map excels here: critical navigational landmarks like trig pillars, cairns, stream crossings, ancient stone circles or standing stones are all clearly shown. OS Explorer also offers some useful and unique features not found on other maps, e.g. it clearly marks all common land where you are legally free to roam away from tracks and paths.

The Harvey map is forced to prioritise a bit more by its smaller 40K scale but gets the balance just about right. As it is a specialist map for walking, the detail shown is pretty much perfect for this activity. Even so, I would prefer it if archaeological features like ancient stones circles and markers were shown a bit more prominently as, on Dartmoor, there are a lot of them and they’re important navigational aids.

The detail and comprehensiveness of Dartmoor’s Splashmap is really impressive given it’s all built on free data. At first sight there’s hardly any difference with OS or Harvey, except for style. After some inspection, however, there are a few noticeable omissions. First, the Splashmap doesn’t show the expansive military ranges. On Dartmoor these are a key feature as they can be off-limits to the public on certain days. Then there is something weird going on with car parks. A big one I’ve recently used near Willsworthy Camp isn’t on the map but others, near Okehampton Camp, are on it even though I’m pretty sure they’re off-limits (military use only). The Splashmap is also missing archaeological navigation features, and the place names can be a bit hit and miss (e.g. the prominent Yes Tor or Haytor Rocks aren’t marked, although the vast majority of tors are).  Still, this is version 1 of a new product created by a garage start-up, so I’m inclined to cut Splashmaps a bit of slack (and we’ll come to its unique selling point in a minute). Besides, OS and Harvey don’t get everything right either. On my recent walk near Belstone I came across this prominent standing stone (at SX 640 925) which, for some reason, isn’t shown on any of the maps:

The missing stone.

The missing stone.

Verdict: No map is perfect but OS is best for overall detail, and Harvey takes the prize for fitness-for-purpose. Splashmaps still have a bit of catching-up to do but greatly exceeded my expectations on what is possible with open data.

Tracks and paths

Walkways are a bit of a bugbear of mine. Maybe I’m too simplistic but as a walker I’m really not interested in whether the trail I’m walking on is a track, footpath, bridleway, green lane or whatever. Combined with rights of way, the different types of routes can result in a baffling array of line styles.

Basically I just want to know if there is a path of any kind, and whether I’m allowed to walk on it. If the answer to both questions is yes then great, just show it in a single style. If there is no right of way, it should just be greyed out. End of story. Cyclists would no doubt disagree with me here – and that is the inherent problem any mapmaker faces. How do you keep everybody happy? You don’t. (But more on this later.)

Still, none of the maps satisfy me here. Whether OS, Harvey or Splashmap, walkways tend to hide in plain sight, and I always need to look twice before I’m sure to be looking at a path and not something else.

Ironically Harvey is the worst offender here. It uses a different symbol for every type of track, path, road, or long distance trail, and then again a different one for every type of right of way. This results in a confusing medley of solid or dotted lines, often overlaid with tiny circular dots of different colours or sizes. OS Explorer gets an out-of-jail card because its larger scale works well on the featureless moors, but I’ve had problems in other places such as the Lake District. The Splashmap thankfully uses much fewer categories for walkways – hooray! – but then chooses to paint them purple which is hard to distinguish from the brown contours. Which explains the need for orange lipstick.

Verdict: All are unsatisfactory in different ways but Splashmaps are on the right, err, track.

Grid reference markings

grid square

This has been another frustration over the years. You want to take a quick GPS position and then check where you are on the map. This normally takes a few seconds – except it doesn’t, because eastings and northings aren’t marked on every grid square. So you end up unfolding the map, read the grid reference off the nearest markings, then trace your way back to your location, which may well be on the opposite side of the fold. By that time you will have forgotten what the GPS reading was, so you start again… If you’ve ever attempted this in a howling gale or horizontal rain, you know what I mean. This is where digital mapping devices come into their own – as long as they are waterproof and their battery lasts all the way.

OS Explorer repeats grid references every 10 kilometre squares in both directions. Harvey uses a more irregular spacing of 10 x 7 (or more, depending where you are on the map), but the dark blue font used for grid references is hard to see as it blends into the map. The Splashmap uses a spacing of 14 x 14 squares. Like OS, it uses a light blue font that is easier to spot than Harvey’s, but the spacing is far too wide to be useful. However, as the Splashmap is made of fold-free fabric it eases the task of panning along to your nearest grid reference.

Still, I’d really prefer something like a 4 x 4 spacing. This is baffling as it would be easy to fix. Am the only one who is having this problem?

Verdict: All unsatisfactory, or maybe it’s just me.

Map material and waterproofness

Britain is not renowned for its dry weather. Combined with regular breezes blown in from the Atlantic, the experience of unfolding a map can be like being slapped in the face with a wet fish. A good map needs to be rip- and waterproof.

The pure paper versions of OS Explorer don’t last 5 minutes in the wilderness, but the more popular ones (including Dartmoor) also come laminated. Although very sturdy and waterproof, the lamination is heavy and bulky, and after a while ends up with bubbles and stretch marks along the creases. With OS Explorer, I also don’t like that the map is double-sided because, just like a piece of buttered toast falling on the floor, I always open the wrong side first.

Harvey’s map is made of thin polyethylene which feels like paper even though it is a plastic material. This makes it totally waterproof, highly rip-resistant, lightweight and nice to hold. It just smells a bit odd. But as far as ‘paper’ maps go, Harvey used to be best in class.

I say ‘used to’ because that was before Splashmaps arrived on the scene. It’s like one of those revelations, “why has nobody thought of this before?” As it turns out, some people have. Splashmaps are inspired by the fabric maps used by pilots during World War II. These maps could be hidden in clothing, didn’t rustle, and doubled up for multiple uses such as a sling or bandage. Splashmaps have taken this concept into the 21st century with a high-tech fabric that enables a high quality map print whilst being fully washable. The fact that I can carelessly stuff the map into my pocket like a handkerchief, and then pull it out – wholly or partially – without having to faff around folding the map, is a total winner. The fabric doesn’t crease even after being left squashed and crumpled in a pocket for a few hours, and the material makes it really easy to grab your area of interest.

A wet day on Dartmoor: Splashmap in its element.

A wet day on Dartmoor: Splashmap in its element.

The only issue with the Dartmoor Splashmap is its size (it’s like a tablecloth) but thankfully its creators resisted the temptation to print it double-sided. Maybe I’ll just cut the map into bitesize pieces… But the material is awesome.

Verdict: The Splashmap literally blows the competition out of the water.


All three map providers offer customisation options, although I’ve never tried any of them myself. With a few clicks on their website, both OS and Splashmaps allow you to order a map centred on your exact area of interest.

Splashmaps also have a service to print standard OS Explorer maps onto their fabric – this could well be the way forward if you want the best of both worlds, albeit a bit pricey. Splashmaps and Harvey also offer bespoke mapping options for particular needs, although for some of these you may be better off printing your own map with a digital solution like Anquet or MemoryMap. On the hills a disposable sheet of A4 paper (wrapped in a plastic sleeve) can be quite a good option, but it requires a bit of an upfront investment in software or data.

Verdict: Try it for yourself.

Open data to the rescue?

I’ve tracked developments in open data for years, so I’ve known what’s been available. But based on the Splashmaps experience the overall quality of this data is still a bit of an eye opener to me. Sure, there are a few glitches that need ironing out but that is just a matter of time.

Open data could well be the gateway to greater choice in personalised or custom maps. Inspired by Splashmaps, I downloaded the 50k terrain and vector data from Ordnance Survey into my GIS software (if you’re new to this, try QGIS). The quality really is very good, and it made me wonder whether I should start making my own maps for personal use, exactly the way I like them. I realise this isn’t an option for everyone but that is where companies like Splashmaps come in. Is there a new market opening up after all?

As you read this, you may be wondering why you should pay for a map that is entirely based on free data. Well, anybody who has ever made maps professionally knows how much work is involved in designing a good map from raw information (compiling, reclassifying, merging, de-duplicating, symbolising, and so on). Then there are the costs of production and distribution which, for any physical product, are significant. So only a fraction of the cost of a physical map actually resides in the data. Life is tough in the mapmaking business, so any new entrants working to offer a bit more choice and competition should be welcomed. Kudos to Splashmaps for taking on this challenge.

Verdict: Watch this space.

And the winner is…

Navigational overkill.

Navigational overkill.

Well, this depends on your point of view – and I’m not being lazy here. There is simply no such thing as the perfect map. Whatever you do, a map is always a compromise between reality and abstraction. There are many variables at play, and the ideal map very much depends on your particular use and preferences.

In an ideal world, I would love the ability the print a Harvey map onto Splashmap fabric, enhanced with a few features from OS Explorer as well as personal additions such as grid reference markings and simpler route symbology. Fat chance you say, but why not? These companies complement each other’s offerings, and with ever more accessible digital data and printing technologies (3D scaled models, anyone?) it doesn’t take a huge leap for someone to rearrange (and license) the relevant bits to create new magic.

This is the ground that Splashmaps have begun to break, and hopefully more will follow in their footsteps – on a clearly marked path.


Disclaimer / Re-use:

This review is entirely independent, unscientific, anecdotal and based on personal experience only. I am not an employee, partner, or investor in any of the map sellers reviewed. Use at your own risk. In the outdoors, maps are no substitute for good judgment.

As all material on this blog, you are free to re-use this article under the Creative Commons licence.


2 thoughts on “Which is the best UK outdoor map?

  1. Pingback: Data Viz News [50] | Visual Loop

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