OS maps - 1:25 or 1:50?^

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pinkyrabbity
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OS maps - 1:25 or 1:50?^

Post by pinkyrabbity »

Hi,

I was wondering on anyone's experience and preference to using 1:50 or 1:25 OS maps when navigating around the coast. Which works better and what does it depend on?

Any advice much appreciated.

Esther

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MikeB
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Re: OS maps - 1:25 or 1:50?

Post by MikeB »

Welcome. Interesting question. I use, as does everyone I paddle with, the 1:50 maps - and the majority of us are using paper maps rather than printing from one of the mapping software options available. Yes, the level of detail on 1:25 is great and could be argued is therefore better, especially for poking around complex coastlines.

For me though, the ability to get most of a days paddling visible on the 1:50 map (which admittedly I use in an Ortleib document case, which is about twice the length of a standard map case) means I prefer 1:50 as I seldom have to open and reposition the map during the paddle.

I do often research a route online, and will zoom in to 1:25 or further - sometimes I'll then print a bit for which I want that higher level of detail.

Cost is another factor. However, for hillwalking, especially in some of the more complex areas, then I tend towards the 1:25.

Mike

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Jim
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Re: OS maps - 1:25 or 1:50?

Post by Jim »

I only buy 1:25000 maps because I like them and find them useful for trying to spot possible landing/camping places. I also usually print maps and charts from various programs I have at a variety of scales on A3 paper (which I used to laminate until the boss took the laminator apart).

For long crossings you need to be able to see all the possible landmarks in case you need to take bearings - this may mean arranging the map so you can see a couple of km inland as well as the open water, so use smaller scale maps. For just following the coast it is useful to be able to see all of the days route but not necessarily contiguously, so I use larger scales or 1:25000 maps in my ridiculously large all clear chart case arranging them so I can flip it over and use it from both sides.

For something like a trip around Kerrera (Oban sea kayak race in fact) I can just about squeeze the whole island onto a side of A3 (not sure what scale that map is), so I made up an OS map on one side and a chart at similar scale for the other side and laminate them together so I can flip over to see land marks or navigation marks as I require. I don't even know what the scales are or if I printed them to a particular scale, between them they certainly show enough detail for racing around the island. There isn't much need for route finding as long as the race leader knows the way everyone else can just follow, but I like to glance at a map/chart to monitor my progress.

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Re: OS maps - 1:25 or 1:50?

Post by e-wan »

I am also considering this question but debating whether to laminate maps or use a map case, I was thinking that laminated might be easier for use of china graph pencils for plotting lines on

does anyone have any thoughts on the pro/cons of laminating versus using a map case or suggestions for an appropriate map/chart case

for people who do laminate maps is A3 an appropriate size

another option is the free1:10,000 ordinance survey data set which is good for coastal detail particularly rocks and beaches,

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Douglas Wilcox
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Re: OS maps - 1:25 or 1:50?

Post by Douglas Wilcox »

Mostly I use A4 laminated OS 1:50,000 computer print outs on deck, sometimes I print them out bigger than actual size because of my eyesight. I never bother about the exact scale because I can just count the kilometre squares. I found A3 too big and the laminate cracks if you fold it. I can annotate tidal flow information before laminating. I use an indelible ink marker to write ephemeral data such as tide times on the laminate (it comes off for future trips with acetone).

I sometimes print out A4 charts to laminate if there are significant shallows in tidal areas or if I am paddling at night in an area with light buoys etc.

I sometimes take a 1:25,000 map A4 laminate of a particularly complex area, not for navigation but for spotting land based points of interest: monuments, ruins, graves, caves etc etc..

I usually print out 1:250,000 OS road map of the general area for macro planning or unexpected route changes. For example, I recently planned a circumnavigation of North Jura involving the Corryvreckan. However, a late change of forecast to a F4 easterly through the Corryvreckan caused a last minute change of plan to a circumnavigation of the southern half of Jura. We did not have 1:50,000 maps of this route but the 1:250,000 map was more than adequate. I use a punch to put holes through the top of the laminate (avoiding the map as it will leak there) then I can thread some bungee elastic through several laminates and tie one end to a deck elastic and keep the laminates under my camera bag or deck elastics.

I have 1:25,000 OS and Navionics charts on my phone and can consult these on land.

Douglas

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Re: OS maps - 1:25 or 1:50?

Post by allan09 »

I tend to use 1:50 but due to failing eyesight print it out from something like Bing Maps onto A3 or zoomed in on A4 to give me half a chance of being able to read it once its on deck. Should be laminating these but just put them into a large (?A3) Ortlieb I have with usually the day's planned paddle on 2 sheets of paper back to back so I can just flip the case over.

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Re: OS maps - 1:25 or 1:50?

Post by e-wan »

thanks,

I think I may try printing out OS maps and laminating them in A4

any thoughts on what the most user-friendly software/website to use for printing OS maps is from a Mac.

Ewan

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Robert Craig
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Re: OS maps - 1:25 or 1:50?

Post by Robert Craig »

e-wan wrote:... thoughts on the pro/cons of laminating versus using a map case or suggestions for an appropriate map/chart case

for people who do laminate maps is A3 an appropriate size ...
I used to use a map case: now it's laminated all the time. I found that the map in the case often needed to be refolded - and so got wet. Also, map case flaps about, laminated maps stay "stuck" to the foredeck.

Tried but rejected A3 as being to awkward: I use A4 all the time now. Usually a stack, with one 1:250,000 and several 1:50,000. Haven't contemplated 1:25,000.

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Douglas Wilcox
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Re: OS maps - 1:25 or 1:50?

Post by Douglas Wilcox »

Image
Sometimes I might print out something else...like the Royal Navy The Queen's Harbour Regulations!

Douglas

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Re: OS maps - 1:25 or 1:50?

Post by richb250 »

I've found 1:50 000 most useful, as you need a large area of 1:25 000 (relative to a kayak deck) to cover a sensible day's paddle. In general, I find the detail sufficient, but I can see the appeal of a larger scale.

It's actually fairly straightforward to set up a website to display the data that the OS will let you use for free. Copying the tidal data from pilots by hand seemed old fashioned to me, so I've started recording it in digital form. In case it's useful to anyone, the maps are linked from http://www.rocksandroots.org.uk/seakayak/

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MikeB
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Re: OS maps - 1:25 or 1:50?

Post by MikeB »

Fantastic resource! Thanks for linking that. I'll include that in the Almanac / Trip Planning page, and the Navigation page too.

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lg18
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Re: OS maps - 1:25 or 1:50?

Post by lg18 »

Like Douglas, I use mainly laminated A4 1:50,000, but for complex areas, e.g. Shetland with lots of ins and outs, caves etc I laminate 1:25,000, and also laminate road map (1:250,000) for some areas in case there's a change of plan and we go off the map/emergency/need alternative route back to car etc etc. We do also have a map case and it does often come in a handy when I frequently forget the laminates!

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Jim
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Re: OS maps - 1:25 or 1:50?

Post by Jim »

I have to confess that a lot of times if I go on a trip with Douglas I leave the maps and navigation to him :)

Most suitable size depends on your deck/cockpit layout. I had loads of room for A3 on my Sea King and can just about work with A3 using the spraydeck elastics on my Taran, but clearly from the photo A4 is a better size for Douglas' layout.

Ravenglass seaquest maps are always A3, that must be coming up in the next couple of weeks....

pinkyrabbity
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Re: OS maps - 1:25 or 1:50?^

Post by pinkyrabbity »

Thanks for all the great comments.

I too tend to use 1:25 and have used both laminates and mapcases. I do like using just smaller than A3 (print to A3 size but leaving white space around the edges to cut down more easily). Sometimes these are just too far away from me under deck lines so now I need to fix something that ties my map case to my spraydeck!

I've also used multiple copies of a map and then arranged them within my map case to allow more coastline to show. It does mean losing inland information though so pros and cons here.

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Re: OS maps - 1:25 or 1:50?^

Post by rockhopper »

Can I recommend the Axel Pack map case which is on Justine Curgenven's site. Designed so that it rolls the map up in waterproof roll which you then just unroll to the section you need.... no more wet or wind ravaged OS maps :
http://www.cackletv.com/shop/axel-pack-map-case.html

Rog.

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