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Maps for Walking, Hiking, Rambling, Running & Cycling

Navigation blog

Welcome to the HARVEY Maps blog on all things Navigation.

Here you will find insightful articles, useful tips and interesting stories on navigating outdoors, written by HARVEY Ambassador Nigel Williams.

March 2019 - Global warming
February 2019 - Winter clothing tips
January 2019 - Winter Munroing kit
December 2018 - Be Avalanche Aware
November 2 2018 - Altimeters
November 1 2018 - It's Getting Dark
October 2018 - The psychology of getting lost
March 2019

March 2019

Global warming
by Nigel Williams

Today (Friday 15th March, 2019) there will be a "Global Climate Strike for the future - The beginning of great change". Greta Thunberg, the remarkable 16 year old Swedish schoolgirl, spoke at the Davos conference urging the world's most powerful, influential and wealthy people to act on climate change and the IPCC report is worth a read.

Predictions of warming are impacting, and will further impact, topography and mapping, so here is a parochial view of a few aspects that might affect the walker.

If temperatures rise by as much as 2 degrees over the next 30-50 years, sea levels around the UK could rise by over a metre.

The impact on mapping is obvious in Alpine and Arctic regions where glaciers and ice fields are shrinking and disappearing altogether. Around the UK the coastline would be the most obvious area to change as it is the lowest lying land.

On all Harvey maps, the High Water Mark or the high tide line is shown as a thin blue line. The line can be used as a safety aid for walkers to help them choose when to access coastal areas on long distance paths that integrate beach and coastal rock (such as the Anglesey Coastal Path – see image) or when to use an inland alternative route.

Mapping these lines has never been an easy task as it can often depend on the time of day the aerial photos used for photogrammetry were taken. However, there are several clues to assist in the interpretation of the images and photogrammetrists look for a mixture of natural signs to plot the high tide line. These can range from change in beach slope, drift lines on the beach and the change in colour of coastal rock. There is a significant skill involved in looking for these signs that requires years of practise. During the ground survey stage, these lines are checked and altered accordingly to give the clearest picture to the end user.

Should sea levels rise then not only would those lines need to be recalculated and re-drawn but every black dot (ground survey) spot height on our maps would need to be changed. Whilst contour lines would remain as they are all the contour numbering on every map would have to be adjusted.

Could Ben Vane become a Corbett? Will the Munro, Corbett, Donald and Marilyn tables all have to be re written? Could there be pre and post global warming rounds, the earlier ones being harder with cumulatively several hundred metres more height climbed?

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February 2019

February 2019

Winter clothing tips
by Nigel Williams

Let’s start with a good pair of stiff soled walking boots. If you can twist the sole they are likely to be too soft for winter. A small amount of toe flex is to be expected in a walking boot but the key issue is having crampons that are compatible with the boot sole. Boots are graded for flex from B0 lightweight trail shoes unsuitable for crampons through to B3 for a rigid winter climbing boot. Crampons are graded from C1 to C3 according to their flexibility and attachment method. The crampons should match the boot. Take your boots to the retailer when you want to buy a pair.

A good quality rucsac around 35 - 40 litres with a traditional lid pocket works well. Line it with a separate dry bag or water proof liner. (Rucsac covers in winter tend to get blown away or collect blown snow).

Gaiters are good in winter to stop snow going into your boots. I wear mine under waterproof trousers as any snow has to go up inside the trouser before it can travel down into the boots and melt. Wearing them outside trousers allows rain and snow to travel straight down into your boots.

Take your walking boots with you when buying a pair of walking trousers. Nothing worse than finding you can’t get your new trousers on over your boots in pouring rain or snow and have to remove them. Longer side zipped trousers are more expensive but they are quick to put on without needing bare hands to fiddle with boot laces.

“Cotton kills” is an old adage, a good thermal base layer is a must. A buff is also a simple light and versatile piece of clothing that around the neck is almost worth another thin layer.

As an extra warm layer many mountaineers carry a synthetic duvet type jacket referred to as a belay jacket which will keep you warm even if wet. Down is for dry cold weather which is not the norm in Scotland.

A good pair of outer mittens or gloves that are waterproof is also an essential piece of kit for me. Gloves are very difficult to make waterproof with so many seams. Mittens are easier and warmer but tricky if manipulating a compass.

No piece of winter kit works in isolation. It is the sum of the whole set of clothing and equipment and one weak link can often expose others on a bad day.

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January 2019

January 2019

Winter Munroing kit
by Nigel Williams

I’m often asked, what is the most important piece of kit to carry for a winter hill day? My answer is ski goggles! Strong wind with snow and ice particles blasting your face hinders navigation skills from route finding and avoiding hazards to basic map and compass work. They’re awkward to carry, but can be a life saver. Tinted ski goggles are good for seeing the terrain, clear lenses make the map easier to read. It’s really worth paying more for anti fogging goggles. Condensation often freezes on the inside and is almost impossible to sort until back in a warm environment. Also check compatibility with wearing reading glasses if required.

Having the kit, ice axe & crampons etc. and the skills to use them is often talked about. Making the decision to use or change equipment before things get fraught however seems to be all too often overlooked. Spare warm layers, hat, gloves and/ or mittens in waterproof bags and accessible doesn’t require knowledge of use, but once hands are cold and wet it is difficult to carry out the simplest of tasks. It also impacts one’s ability to make sound decisions and use the skills.

Walking poles (ideally a pair) with a large snow basket are invaluable on soft snow in easy terrain, BUT the timely decision to put them away and replace with an ice axe is critical.

GPS as a quick location confirmation tool rather than a navigation tool. However touch screens rarely work in poor conditions or wearing gloves.

Head torch for an early start, although errors in planning and decision making often lead to it being used at the end of the day.

“Group shelter” a useful item not just for emergencies, it is a light wind proof (not waterproof) nylon bag that can be pulled over the top of a group. With everyone huddled inside it soon warms up and enables people to sort equipment, take on food and check the navigation.

A 4-6 person size is probably most useful. A 4 person one works for 2 people but not the other way around. If you can’t get the whole party inside even split between several shelters there may be a reluctance to use it and leave someone stood outside in the cold. However not having one leaves no option of shelter for anyone.

This piece may appear to be about safety kit for a winter mountain day, but it is also about planning and timely decision making.

Example of Winter Munroing Kit:
1. Rucksack
2. Warm and waterproof layers (plus spares)
3. Head torch
4. First Aid Kit
5. Gloves or Mittens (plus spare)
6. Hat (plus spare)
7. Ski goggles
8. GPS device
9. Map & Compass!
10. Watch
11. Emergency Shelter
12. Ice Axe
13. Walking Poles
14. Crampons
15. Dry bags (for keeping spare kit dry)
16. Warm drink/food

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December 2018

December 2018

Be Avalanche Aware
by Nigel Williams

The Scottish Avalanche Forecast started at the weekend as storm Deirdre arrived, and now it looks like we are going into a period of warmer weather. But that gives us time to think about the realities of travelling in the hills safely at this time of year. There is sometimes a view that it is climbers that get avalanched. Look more closely at the statistics and it becomes evident that “climbers” tend to get avalanched on the approach to their climbs or on their descent, often on ground around 30 - 45 degrees (the most common angle for avalanches to occur). Whilst those sorts of angles are steep for many walkers they often appear attractive with the ground being smooth and presenting the option of a shorter route in ascent or descent.

Avalanche education over the years has changed. In the 1970s and 1980s it was all about the (existing at that time) science of snow. In the 1990s and early 2000s this changed more to a testing of the snow pack approach. In the past 15 years it has moved to avoiding the avalanche terrain through proper planning and thought processes before and during our journey and an understanding of heuristic biases. It is amazing how many people who have survived an avalanche will say that they thought the slope might be suspect yet still carried on. So why do we do this? Heuristic bias; a short cut decision making process our brain makes which overrides our critical risk management thinking. For example, you see fresh footprints up a slope that in your planning you had identified as a potential avalanche risk. But now on the ground, knowing it would shorten your route, you decide it must be safe.

The problem we all face with the subject is that 99% of the time the feedback we receive is that we made the right judgement when we have fallen into these biases - unless we actually get avalanched! Heuristic biases are fascinating and there are at least half a dozen more identified in relation to avalanche incidents and even experts are prone to them. In reality today we employ a range of all of this knowledge and practical skills which complement each other.

Gone are the days of stopping at a phone box and trying to get a recorded weather forecast when you are already on your way to the hill. Planning has changed hugely in the last couple of decades with improved weather forecasting and the existence of the Scottish Avalanche Information Service (SAIS) which enable us to start the process several days ahead of our trip. It is worth remembering though that these are forecasts and on the rare occasions that the weather forecast is inaccurate then it is likely that the avalanche forecast reflect this. The Scottish Government, largely through sportscotland, is actually investing a lot of money into trying to keep us safe in the mountains in winter.

Check out the SAIS website and spend time learning about the subject. Planning and avoidance (which may mean higher than summer navigation skills) is the key. There is also a Be Avalanche Aware mobile app.

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