GPS - Any preferences?

Places, technique, kayaks, safety, the sea...
Post Reply
Matt O
Posts: 51
Joined: Thu Sep 02, 2004 2:04 pm
Location: North Yorkshire

GPS - Any preferences?

Post by Matt O » Mon Jan 10, 2005 1:27 pm

I have had fun 'playing' with various digital map software packages over the past few months. I have also noticed that the good Dr Wilcox has indulged for Xmas in some fancy new GPS kit... (very nice!)
Is there much interest in GPS amongst sea-kayakers or is it just a 'toy'?
Do people have any experience of/preferences for particular software, types of maps, charts etc
Personally, I have enjoyed the benefit of having access to a GPS unit while out on the water, not as a primary navigation tool but as a backup.There is no substitute for the old ways with a chart and compass!. Also I have been pleasantly surprised at how accurate my traditional navigation skills (learnt mostly from mountaineering) are in what is still, to me, a relatively new environment. Without reference to GPS I would have doubted my own reckoning and speed of progress especially in more open situations.
Any comments most welcome....
--- Matt ---

User avatar
Geoff Seddon
Posts: 283
Joined: Thu Jul 29, 2004 11:04 am
Location: Horwich

Post by Geoff Seddon » Mon Jan 10, 2005 6:01 pm

Absolutely brilliant, particularly for sitting in races, staring at the read out and yelling "Hey we're doing 16 klics" to anyone who can hear. At my age it is the biggest screen I can get and mapping software from Memory-map, a few salient waypoints put in before the trip from the PC, print off 1: 50,000 map with tidal stuff put on and away you go. They are exceedingly usefull for ferrying streams as there is no need to "aim off", your actual track is what is shown, rather than where your boat is pointing, so you can tweak your ferryglide angle, as different rates of flow are encountered, to reduce to a minimum the number of paddle strokes required. When travelling with, or heaven forbid against, tide they are very usefull to "hunt" for the most assistance. On top of all this a GPS tells you EXACTLY where you are, all the time, provided the batteries haven't gone flat, you haven't got water in it and you are not in a snowstorm.

Matt O
Posts: 51
Joined: Thu Sep 02, 2004 2:04 pm
Location: North Yorkshire

GPS - Usefulness vs Cost

Post by Matt O » Mon Jan 10, 2005 7:14 pm

I am wary of becoming 'too' reliant on something that has batteries, although i admit it has been a very useful tool especially on the few more exposed crossings I have undertaken. I can see great benefit of knowing your realtime position in poorer weather conditions or more importantly an emergency situation.
I would like to be able to use it more widely but I reckon I will be bankrupt or divorced (or both) if I buy any more maps especially at Memory Map prices!
The one advantage with Memory Map though would appear to be that you can get both OS 1:50000 and also 1:25000 along with Maptech marine charts to work all from within one package.
Now, do I buy more maps, go new places with old poly kayak or do I scrimp and save in the vain hope I can afford a new P&H Quest? - oh yes it will be mine....
--- Matt ---

User avatar
Jim
Posts: 13497
Joined: Sun Apr 21, 2002 2:14 pm
Location: Dumbarton

Post by Jim » Mon Jan 10, 2005 10:23 pm

Normally when I'm out there are at least 2 of us with GPS units and spare batteries, I think when I was in the Summer Isles with Geoff we probably had around 6 units spread through the group - no worries :)

There are a lot of units out there, like Geoff says get one with a display you can see, for me the original etrex may be a low res screen with very features, but it is the same size as all other etrex screens so it is less cluttered :) There are better units now with better screens and a chartplotter like Douglas' is going to be the ultimate!The other thing I would look for is PC connectivity, some cheaper smaller units don't have any sockets to attach them to the PC, which makes them hopeless in my opinion. The method for getting waypoints into such a unit in advance is generally tortuous and tedious, what you want to do is make up a list from your mapping software and then transfer at the touch of a button (and then plug in your mates GPS and upload to it as well!).

As for using I generally mark up waypoints on OS maps or copies of with 3 digit (or 1 letter and 2 digits) codes beside each one. I tend to mark prominent points around coastlines about 1-3km apart, and then bays or jetties and places that might be worth stopping or camping. I can then put in routes with different code letters for primary routes, alternatives, extra legs if we are ahead and even escape routes - my GPS can only take 1 route but as the waypoints are alpha numerically coded they sit together so it's really easy to rejig a route on the go. Because I keep my waypoints close I am generally never more than a km or so from one so as long as I know which waypoint I was last heading for and which direction it was in (always keep track with map and compass too) I can switch back to old fashioned navigation at a moments notice.

For open crossings you will be maintaining heading with your compass, but the GPS is great for seeing if your track is straight or not so you can modify the heading as Geoff describes to keep you on the shortest ferry possible. Again you will be tracking your position on the map and trying to spot any landmarks so even if the visibility does come down and the unit fails you should have a pretty good idea what heading you need, and also roughly how far you have left both in time and distance if everything stays the same (they don't tides vary) which means you have a pretty good idea when you should see land again which may just suppress panic for what would otherwise be anxious minutes or hours!

Fantastic things, use with your normal navigation skills, not instead of!

JIM

User avatar
capsized8
Posts: 536
Joined: Wed Oct 20, 2004 4:57 pm
Location: north wales

GPS

Post by capsized8 » Tue Jan 11, 2005 12:24 am

Hi, Good advice and pointers (scuse the pun) from Geoff and Jim.

I will however add this for you to ponder on. Do you intend to purchase (assuming you dont already have one) a handheld vhf radio ?

If you are then I would urge you to consider a combined VHF/GPS/DSC unit made by Uniden called the Mystic. I dont believe there are any others out there as yet. I can honestly say, "brilliant piece of kit for on the water" all in one package and yes it is waterproof. Well tried and tested by myself in force lumpy and wet !!

_________________
peace and good padlin.
pete
peace and good padlin.

Matt O
Posts: 51
Joined: Thu Sep 02, 2004 2:04 pm
Location: North Yorkshire

GPS -Pros & Cons

Post by Matt O » Tue Jan 11, 2005 12:28 am

Thanks for the advice Jim - I definately agree with your last statement!

I apologise if I hadn't made it clear but I already use a GPS unit connected to a PDA. As with a chartplotter you get your real time position and track plotted on screen. The advantages over etrex/garmin type units would appear to lie in the ability to adapt routes as you paddle. With a PDA I can select any point and choose to navigate to that location. I can hear you all questioning the sanity of someone taking a PDA out on the water, but stored lovingly in an AquaPac case it has survived a whole year unscathed. I have seen an Otterbox waterproof case specifically for PDAs but at no small cost....

I was also attempting to canvas the opinion of others about the differing software packages available, pros and cons, ease of use, (prohibitive) cost, experiences of use in the kayaking environment, planning trips etc

More views please....
--- Matt ---

User avatar
tpage
Posts: 481
Joined: Tue Aug 03, 2004 1:44 pm
Location: Glasgow

technology!

Post by tpage » Tue Jan 11, 2005 9:08 am

Ive had a Garmin Etrex for about 3 years, it does the job fine. And I think Ive switched it on a couple of dozen times. It still have the original duracell batteries in it. I must say I prefer to take in the scenery, correspond it with the deck map and get away from electonic devices when I am seakayaking. Now where did I leave that sextant?- Tony

willsc1
Posts: 67
Joined: Sun Sep 21, 2003 10:17 pm

Post by willsc1 » Tue Jan 11, 2005 1:08 pm

I have been using GPS for quite a while now and find it very useful. I rarely use it for position(honest!), like you say Map & Compass etc. should be the prime reference for this.

However I do use it a great deal for :

Speed - shows when in/out of the flow - good to keep you out of the slack water around headlands etc.

Track - excellent to give you drift when you are doing open crossings with no landmarks. (Difference between boat Compass Heading and GPS Actual Track.) The unit will also give you exact steering info, like Geoff says, very useful.

Exact ETA: also very useful when the tea is in the oven, taxi driver awaiting etc!

Keeps a record of track throughout the trip, useful when stored on PC (I use GPS Trackmaker - freeware), so I can refer back to it later for details/timings of the trip etc.

And of course, for finding my way home in the dark when the novelty has worn off and I just want to get home quick!

I have an Etrex (which I use in the hills) but it is a little too small and fiddly for the kayak in rough weather/the dark. My paddling one is a Garmin GPS 72, large screen & buttons - easy to use single handed in even rough weather. It lies flat nicely on my deck or spraydeck. Though waterproof, I always have it in an Aquapac and so it is still like new after a lot of use! It is only capable of showing very basic mapping, though I have not found this a problem, I like my maps to be map size not 2" square!

It is not too expensive (about £110 I think), but if you can afford a little more the GPS 76/76C/76CS (a lot more!) are the same unit with more memory, colour diplays and better (much) mapping software - though obviously the price corresponds.

JW

User avatar
Douglas Wilcox
Posts: 3519
Joined: Sun May 11, 2003 1:31 pm
Location: Glasgow
Contact:

gps

Post by Douglas Wilcox » Tue Jan 11, 2005 9:08 pm

Before I started sea kayaking I always resisted the idea of a GPS for use on the hill. But I have been using a basic yellow etrex for over 2 years kayaking. I have never bothered putting it in a waterproof bag and it floats. I supose I have used it mostly to tell me speed over the ground which is useful in strong tidal areas. Like Jim I put in major waypoints (like when we did a 15km crossing of the sound of Jura) and the GOTO function is very useful. I knew I was in a countercurrent when the ETA started to get further away! But although it is easy to get waypoints in from a computer, it is a drag using its own interface.

I did get a Garmin Map76CS and I am blown away by it but as I said in another post, Shackleton didn't need one to get around. I primarily got the Garmin for in car navigation, that I can move from car to car, for both myself and my wife. In this role it is simply amazing, better than some built in units costing £1000.

I also got the blue chart software which has every chart, for the west of Scotland. You can load this on your computer and print out charts just like Anquet or Memory map. You can upload your track from the gps and overlay it on the chart on the computer screen. You can create waypoints and routes on PC and download them to the GPS. You can also upload your track into Anquet and overlay the OS map.

But you can also download the entire UK coastline of Charts (if you are very very rich ) into its memory and then track your progress on the chart. Even better, you can simply point at an object on the GPS screen then press GOTO, you do not need to enter a waypoint's coordinates. The blue chart even allows you to click on standard and secondary ports and predict the tides for any time past and present.

Unfortunately Anquet and Memory Map use raster (bitmap) maps like a compressed photo with every pixel stored in memory and you cannot load these into Garmin GPS units. In the States you can buy a topographical map like our OS for the whole of the USA for £35! This is a vector map, each pixel is not stored in memory. If a large triangle was represented it would consist of coordinates for its three points and a description of what the joining line was like.This will not happen in the UK as currently OSGB has no intention of producing a Landranger vector map.

Something that surprised me greatly was that I have the gps map set for the wGS84 chart datum which the bluecharts use rather than the OSGB datum that the OS maps use but when I imported into Anquet the track was bang on. When I first got my etrex the datum was set at WGS84 (the default) and when I read out the OS grid references and checked them with trig points, the grid reference was always about 100 meters too far to the west.

Whatever, I have a fantastic toy for kayaking, but it is so expensive that I would only recommend one with chart plotting capability if you need in car sat nav. A basic etrex or similar + Anquet/Memory map is all you really need.

I could have bought a very respectable kayak for what I spent on the GPS76CS and car and marine maps!

Douglas :o)

User avatar
seismicscot
Posts: 224
Joined: Thu Feb 19, 2004 12:05 am
Location: London

Post by seismicscot » Wed Jan 12, 2005 11:30 am

May I also jump on the bandwagon as well as solicit recommendations for UK coastal maps to upload onto my Magellan Sportrak Marine Pro?

I bought my GPS unit whilst living in the US, so it is loaded with west coast US maine data. It claimed to have European coastline data as well, albeit at a lower resolution. However, while up in Skye over Christmas I noticed that Skye, and indeed most of the Hebrides, are missing! Recommendations for marine map sources would be very welcome.

Cheers,

Clark
Clark Fenton

Matt O
Posts: 51
Joined: Thu Sep 02, 2004 2:04 pm
Location: North Yorkshire

GPS - In Depth...

Post by Matt O » Wed Jan 12, 2005 11:59 am

Great to hear about your new toy, Douglas... you continue to excel yourself with the ability to turn others green with envy, be it with the weather, location, stunning photos etc and now fancy gadgets. Keep up the good work!
For the very reason you mention about vector maps being unavailable in any sensible scale for the average user from our friendly National Mapping Agency most of us have had to resort to using Memory Map, Anquet or some other such program. Raster maps do create huge file sizes although Memory Map seem to have successfully compressed the file sizes without any noticeable loss in quality.
Using a PDA hooked up to a GPS reciever allows me to use these raster maps and with the low cost of memory cards at present I can easily store files for large areas of coastline or mountain terrain, and better still switch between different scales of map and also TomTom SatNav software when I get back into the car!
I also like the ability to switch between marine chart and OS map at the push of a button/tap of the screen while out on the water.

Douglas -There is a simple explanation for your surprise at the accuracy of your track when imported into Anquet. My understanding is that all GPS units/satnav programs use the WGS 84 datum... the clever bit is how they convert this data to fit with the OSGB 1936 datum used for the National Grid and so that it shows your position/track accurately on the OS raster maps. I have both Marine charts and OS maps in Memory Map and you can immediately see from the map outlines that they use a differing datum.
With Memory Map (Euro edition) it is possible to scan in your own maps and calibrate these very accurately and then import these into MM OS edition. Quite time consuming but worthwhile for smaller areas of 1:25000 maps. (If anyone is interested in these then please feel free to get in touch....)

My biggest bugbear is cost of the maps. Again this is not necessarily the software providers fault but again down to the Ordnance Survey and their data liscencing costs.

For the moment I will keep paddling my poly kayak, buying expensive maps and gadgets and appreciating all the stunning scenery...!!!
--- Matt ---

User avatar
sub5rider
Posts: 655
Joined: Mon Mar 10, 2003 4:38 pm

Post by sub5rider » Wed Jan 12, 2005 1:01 pm

seismicscot wrote: as solicit recommendations for UK coastal maps to upload onto my Magellan Sportrak Marine Pro?
Clark
It is entirely possible, with a little nous to swap between the European Land and Marine maps on a Meridian; I do it at least twice a year. I would not be surprised if this isn't possible with a sportrak too. I found out how to do it (coz it isn't strictly legal in data copyright terms) off the 'net. Specifically a Magellan based Yahoo group. Nudge-nudge, wink-wink...

;)

User avatar
Douglas Wilcox
Posts: 3519
Joined: Sun May 11, 2003 1:31 pm
Location: Glasgow
Contact:

Garmin blue chart

Post by Douglas Wilcox » Wed Jan 12, 2005 9:07 pm

Excuse the large size but here are a couple of PC screen dumps from the Garmin Blue chart west of Scotland.

Image

You get more detail as you zoom in
Image




Douglas

User avatar
Jim
Posts: 13497
Joined: Sun Apr 21, 2002 2:14 pm
Location: Dumbarton

Post by Jim » Thu Jan 13, 2005 9:45 am

Am I imagining it or does it even show the bridge over the atlantic as a thin black line?

JIM

User avatar
tpage
Posts: 481
Joined: Tue Aug 03, 2004 1:44 pm
Location: Glasgow

Powerline

Post by tpage » Thu Jan 13, 2005 10:18 am

Imagination Jim- the bridge links the mainland to Seil not Seil to Luing. Thats a power line you are looking at.

Fantastic charts by the way Douglas. You can really understand why the tide pumps around Fladda, Belnahua and Ormsa when you see the change in seabed profile. Tony

User avatar
Jim
Posts: 13497
Joined: Sun Apr 21, 2002 2:14 pm
Location: Dumbarton

Post by Jim » Thu Jan 13, 2005 6:31 pm

I thought the sound was straighter than that!

I'll try and remember not to make that mistake when paddling out there!

JIM

guy
Posts: 556
Joined: Fri May 02, 2003 10:24 am
Location: North Cumbria

Post by guy » Fri Aug 19, 2005 4:47 pm

the Scottish Mountaineering Club http://www.smc.org.uk/ have some free vector maps for use on newer garmin GPS units

http://www.smc.org.uk/books/books_contour_maps.htm

the maps are derived from a radar scan of the earth by the space shuttle


probably not too much use to sea farers but if Skye is missing then it imay be of some use

User avatar
Erling
Posts: 497
Joined: Thu Aug 25, 2005 12:56 pm
Location: Norway
Contact:

Post by Erling » Thu Aug 25, 2005 1:09 pm

I have owned a Garmin 60CS since spring last year, and love it. I use it in the car with autorouting software (City Select Europe), when trekking in the mountains - and when paddling (using topographic 1:50,000 maps). This summer the wife and I did a few days of camping and paddling along the shores of Northern Norway. In this myriad of smaller and larger islands, we would probably have been still paddling had we relied on the paper map only.

Unlike the 76CS it doesn't float (it doesn't sink either...), but used inside my clear plastic Aquapac case the difference doesn't matter.

From Sleneset, Northern Norway. Recommended!

Image
The older I get, the better I used to be.

john campbell
Posts: 97
Joined: Sat Feb 19, 2005 5:26 pm
Location: Ayrshire

Garmin 60

Post by john campbell » Sun Aug 28, 2005 8:25 am

I picked up a Garmin 60 a few months ago for paddling and hillwalking and it is fantastic - all the functions I will ever need and more with a screen size which is easy to read from the boat. Great battery life and waterproof. Amazon had them for £115. Definately worth checking out.

happy paddling
John

Post Reply