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Which GPS to buy


risingsn

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Lots of differences in GPS units. First of all...price. Then, memory, screen size, color or B&W, mapping software etc.

If all you want to do is keep track of speed and distance and set cookie trails to find your way home, some of the less expensive units will work fine. The Garmin eTrex basic is a good unit for about $99.00.

If you want a GPS with mapping capabilities the price starts to go up. The Garmin eTrex Legend has 8meg of memory for maps, a B&W screen for about $169.00.

The next step up from there is to go to a unit with a color screen (easier to see in sunlight) we are now into the $300+ range, these units also have more memory for maps. Look at the Garmin eTrex Legend C, Garmin GPSMAP 60CS, or the Garmin GPSMAP 76CS.

I have owned a couple different Garmin units, and currently have a Garmin GPSMAP 60C. It works very well, waterproof, plenty of memory for Blue Chart software (this software costs an additional $149 or so), and a good interface to the PC.

The other company out there is Magellan, I am not familiar with their products.

Try this link to see all the Garmin models http://gpsnow.com/

PS. A GPS unit is not a replacement for good navigation skills.

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I've had three units from Garmin over the past five years. I now have the GPSMAP76CS, which I use on the kayak deck, on the bike, in the car, on the hiking trails, and used to use on my sailboat (now owned by someone else). I agree that the larger color screen of the 60CS or 76CS are fine things to have, and are very easy to read, even in bright sunlight.

I know that the units are all rated to be waterproof, but would recommend a purpose-designed waterproof bag to enclose the GPS on deck, just to be safe. My original Garmin III+ succumbed to water damage through the battery case. Now I paddle with a flexible plastic case fully-enclosing the unit, but allowing easy button manipulation and screen reading.

When the weather grows colder and the alkaline and NIMH batteries start to have rapid fall-off of voltage, I switch to pricey but strong Lithium AAs in the 76CS.

If you do any hiking, the 60CS and 76CS have altimeter functions.

John Gamel

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First I would also echo the idea that a gps is no replacement for good naviagtion skills and a compass and chart. Then I would say that I have found the Etrex to handle all of my gps needs. It remembers where I have been and will tell me (Most of the time) where I am, and how fast I am moving and how far I have gone. It is cheap and has had a couple of problems with water inside it but even with water under the screen it has kept on ticking. The real question you have to answer is what do you want it to do?

Bob L

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It should float, so that if you want to use it outside of a protective bag you won't loose it when you drop it in the water. You need to use it out side of a bag if you want it to run on your deck as it's really hard to see through a bag in bright sunlight.

It should have the largest screen / biggest numbers that you can afford.

You should be able to up load routes and down load way points from mapping software.

Both Garmin and Magellan products have these abilities. Ihave an older simple G-12 which is/was pretty bulletproof but does not flat. I escalated to one of the Magellan Marines, a little high end but durable. One of these days I will get the charting software for it. For me the read at 3 feet test aka on the deck of a kayak in glare was important.

I prefer the ones without any thing sticking out in the way of an antenna.

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Don't own a GPS, may never do so, not that I wouldn't use one but more that I am not prone to adding gear I really don't need, kind of the anti-Crouse you might say. But I will mention that a colour display either translates into bigger/more expensive batteries or shorter battery life.

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Actually...It is just the opposite. If you go to Garmins website and use their comparison chart http://www.garmin.com/outdoor/compare.jsp then choose the Legend and the Legend C, you will see that both units use 2 AA batteries, and the color units battery life is twice as long as the B&W unit. Legend:18 hours, Legend C: 36 hours. My Garmin GPSMAP 60C runs about 30 hours on plain old AA's.

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From a technology standpoint a colour display requires more power to operate and requires more processing to generate the displays. Obviously the product specifications are a better guide that such rules of thumb. As with EPA mileage ratings, organic food labels, etc. the experience of real users trumps both.

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The GPS Map 76CS fits Ben's criteria perfectly -- but it is pricey (should be able to find it under $450). And, you have to add the cost of software, which for charts is about $150 for the first region and $100 for each subsequent. Two regions cover New London to Penobscot, so for reasonably complete coastal coverage out of Boston, the total is around $700.

Plus, if you want to use it for driving, you may want to get the North American City Select for roadmaps (another $100) and an external antenna ($40-70), and other assorted cables and adapters. Once I had the unit, I figured the extra cost of equipping it for driving was not so bad, and I've not regretted it -- it's gotten me unlost more than once. One really neat trick with the roadmap software -- though it hardly justifies the cost of course -- is to hook it up to a laptop, take it on an airplane, get a window seat, stick the antenna to the window, and watch the flight path, ground speed, altitude, etc on the laptop's software. So, you can look out the airplane window and know what you are seeing.

There are also topo maps, but as I've pretty much given up hiking -- guess why ;-)) -- I have not looked into it.

A note about reliability. I've not heard any complaints about Garmin units, but I did have trouble. After a few months, it stopped acquiring satellites. After a session on the phone with tech support, I sent it back. They returned it to me quickly with upgraded software and no other repairs, but it was working. But once again it failed the same way after a couple of months, and this time they replaced it with a refurb unit in excellent condition, which has been fine.

Bottom line -- the benefits of a high-end unit are worth considering, but it is a major purchase and requires fiddling with software to get the most out of it.

I'm happy to answer more questions, here or by e-mail.

--David.

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An appearance of condensation inside an ETrex marks the beginning of the end if it continues to be splashed or submerged ...although it may continue to function for a long time with a less than watertight electronics chamber.

The two halves of the case are held together with a precisely cut piece of clear tape (Mylar, I suppose). While the adhesive bond between the tape and case is strong and won’t degrade, it does not seal out water. The adhesive holding the molded black band around the case does that. It works great for awhile.

This outer band is flexible and subjected to a lot of stress when tightly gripped for button pushing and data port access. The adhesive must also be flexible or it would quickly delaminate. During the warranty period, plasticizers escape from the adhesive which may also ooze out at the edges where gripping pressure is high. Eventually a pathway for moisture opens into the electronics chamber.

A tiny amount of moisture trapped inside will appear as condensation under a cool water droplet. A few drops of water may even move around on the LCD and the unit will still function. But once a drop of salt water shorts exposed leads on the board electrolysis will quickly destroy them. Removing the batteries can prevent the anodic destruction.

The boards are not coated in Glyptol and the cases don’t have a desiccant or a sealed access port to vacuum out the moisture. Those wouldn’t repair the leaking seal anyway. I don’t think Garmin offers a post-warranty seal repair kit.

You may be able to rehabilitate the unit by removing the black band and cleaning off the old adhesive. But don’t remove the clear tape or separate the two case halves. The electronics can then dry through the button openings. You can accelerate this process on a warm dry day by placing the GPS in a jar and drawing on it with a vacuum cleaner. When it’s dried out the batteries can be replaced for a test. I don’t know what adhesive to recommend when gluing the band back on.

The easy way out is to do what Garmin expects and simply buy a newer one that’s guaranteed to function under a foot or so of water.

“Familiarity Breeds Contempt”

-Aesop

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I like my Magellan Sportrac, especially as mounted on deck with swivel display. Larger color display allows reading speedo and running average speed easily. Note that although the Sportrac floats, it will NOT if dumped ON its swivel mount (as happened this summer!). So now I clip the mount to a rigging line.

Around $200 on eBay.

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>First I would also echo the idea that a gps is no

>replacement for good naviagtion skills and a compass and

>chart.

: : :

>Bob L

Depends where you are. If you're threading your way through a salt marsh at low tide and can't see any landmarks, a GPS is mighty handy.

A mapping GPS is pretty nice, although I don't know if color is necessary. My old(ish) Garmin 12Map works fine, although its computer connectivity leaves something to be desired (no USB, and no Garmin works well with a Mac anyway.)

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I have a Garmin Ledgend C and it's a nice small unit. The only trouble I had is that the outer rubber gasket came loose. I sent it back to Garmin and it was repaired free of charge. I like the small size becuse I use the unit while hiking. FishHawk

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I'd recommend not getting one at all. I went through this same process a few years ago: asking for advice from NSPN, checking out all the different models, eventually settling on a Garmin Etrex Legend. i figured it would be a substitute to paper charts, I could keep a log of all my voyages, I could use it to navigate city streets or I could use it for hiking.

2 years later, my Legend is nothing but a dust magnet. For this particular model, the screen is just too small to use it "on the fly". You can't see it on the deck of the boat (or on the dashboard of my car). I haven't tried hiking with it although I don't bother since i have plenty of paper maps. And Bob's point about the batteries is key. When you're on a 6 hour voyage out to some distant island, you don't have the time (or the inclination) to change batteries. My advice would be to save yourself $350 and buy something more useful, like paper charts. At least they don't run out of batteries. :)

Jim Fessenden

"Two Eskimos sitting in a kayak were

chilly, so they lit a fire in the craft.

Unsurprisingly it sank, proving once

again that you can't have your kayak

and heat it too."

VCP Avocet, Aqua

NDK Explorer, White on White

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Due to suggestions from the NSPN archives, I bought a Garmin GPSMAP 76. I found a pretty good deal at $150 on the web.

Whether you need one or not is up to each individual. I don't need it for navigation. For the most part, I can always see my next destination. But I've found it very handy, primarily for speed and distance data. I like to know what kind of difference it makes if I change my paddling style. How much is the current or wind affecting my speed? Last week, I demo'd a friend's boat and found myself going a full mph faster using my normal cadence. I find that good info to know.

Yesterday, we paddled across Duxbury Bay for a bowl of soup. The chart said it would be 2.5 miles. Turns out it was 3.5 miles, after detouring around sandbars. At the end of the day, we have a total mileage reading. I find this handy to know how tired I get after how many miles.

I find the GPSMAP 76 very easy to read, even though my eyesight isn't good. I can barely read a book without glasses. But you can configure the unit to display information in a large font or a ludicrously large font.

I don't believe that a GPS is a substitute for navigation skills, and I've signed up for Doug Lowry's course in November.

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Dear Enchant:

I admire your quest for good data. I have similar inclinations myself so we have something in common. I would just point out that GPS receivers don't discriminate which direction you are going. It all gets added in.

For example, I used my Etrex Legend for kayaking one day when it was quite windy with good sized waves (perhaps 2-3 ft.). At the end of the day, my companions and I were quite surprised to learn that we'd paddled over 20 miles when in fact, by the chart, we had perhaps paddled 15-17 miles. One of my companions concluded that the GPS receiver was also counting each 2-3 ft. swell in its distance measurements (since the unit itself was bobbing up and down in the waves just like me). Initially, I thought my friend was full of hooey since the GPS receivers have a limited degree of precision in their distance measurements but after more thoughtful analysis, I think he was right.

A similar instance was when I took my sister's Etrex Summit hiking in New Mexico. This unit gives you elevation profiles of your hikes which I think is pretty neat. We hiked down to the Rio Grande and I got a nice profile of the descent. On the way up, I let the receiver dangle from a lanyard around my neck. I got a nice elevation profile of the ascent but it was oddly flattened out, as if I'd traveled a much longer distance. After some head-scratching, I concluded that the Arc of the Dangle was being factored into my distance measurements. So with each stride, the thing would dangle back and forth like a pendulum, which the Summit saw as extra distance traveled. So my data was all screwed up.

So these anecdotes are not to discourage you, Enchant, from using your new GPS unit. I'm glad you are happy with it. But hopefully this will improve the quality of your data.

Happy Paddling!

Cmfos

>Whether you need one or not is up to each individual. I

>don't need it for navigation. For the most part, I can

>always see my next destination. But I've found it very

>handy, primarily for speed and distance data. I like to

>know what kind of difference it makes if I change my

>paddling style. How much is the current or wind affecting

>my speed? Last week, I demo'd a friend's boat and found

>myself going a full mph faster using my normal cadence. I

>find that good info to know.

>

>Yesterday, we paddled across Duxbury Bay for a bowl of soup.

> The chart said it would be 2.5 miles. Turns out it was 3.5

>miles, after detouring around sandbars. At the end of the

>day, we have a total mileage reading. I find this handy to

>know how tired I get after how many miles.

>

>I find the GPSMAP 76 very easy to read, even though my

>eyesight isn't good. I can barely read a book without

>glasses. But you can configure the unit to display

>information in a large font or a ludicrously large font.

>

>I don't believe that a GPS is a substitute for navigation

>skills, and I've signed up for Doug Lowry's course in

>November.

Jim Fessenden

"Two Eskimos sitting in a kayak were

chilly, so they lit a fire in the craft.

Unsurprisingly it sank, proving once

again that you can't have your kayak

and heat it too."

VCP Avocet, Aqua

NDK Explorer, White on White

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>For example, I used my Etrex Legend for kayaking one day

>when it was quite windy with good sized waves (perhaps 2-3

>ft.). At the end of the day, my companions and I were quite

>surprised to learn that we'd paddled over 20 miles when in

>fact, by the chart, we had perhaps paddled 15-17 miles. One

>of my companions concluded that the GPS receiver was also

>counting each 2-3 ft. swell in its distance measurements

>(since the unit itself was bobbing up and down in the waves

>just like me). Initially, I thought my friend was full of

>hooey since the GPS receivers have a limited degree of

>precision in their distance measurements but after more

>thoughtful analysis, I think he was right.

That's an interesting theory. I'll have to come to a complete stop during high swells and see if starts ticking off distance with each swell that passes.

I didn't realize that the GPS could calculate altitude. I thought that the altitude reading was a product of the GPS lon/lat reading and the mapping software. So (again, as I understood it), if you were standing at a location that was at an altitude of 100ft and climbed a 100ft tree, the GPS would still say that you were at 100ft. Maybe I'll try to find a tall building and test that.

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>I didn't realize that the GPS could calculate altitude. I

>thought that the altitude reading was a product of the GPS

>lon/lat reading and the mapping software. So (again, as I

>understood it), if you were standing at a location that was

>at an altitude of 100ft and climbed a 100ft tree, the GPS

>would still say that you were at 100ft. Maybe I'll try to

>find a tall building and test that.

No, they actually do use triangulation to compute altitude. You have to be able to receive good signals from (I think) at least three satellites to get a 3D position. But it's not terribly accurate -- even less so than the 2D position which is to within 30-60 feet. Still, kind of neat to turn on your GPS in an airplane and see it reading 36K feet for altitude.

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Yah, I've done that as well. You can also look at the speed of the aircraft during landing (the planes land at about 160 MPH) or when the plane is crusing. And it's also useful if you're flying across country and want to know what the heck you're looking at down below. the only thing is that you need to be at a window seat in order to get a signal.

Jim

>

> No, they actually do use triangulation to compute

>altitude. You have to be able to receive good signals from

>(I think) at least three satellites to get a 3D position.

> But it's not terribly accurate -- even less so than the 2D

>position which is to within 30-60 feet. Still, kind of

>neat to turn on your GPS in an airplane and see it reading

>36K feet for altitude.

>

>

Jim Fessenden

"Two Eskimos sitting in a kayak were

chilly, so they lit a fire in the craft.

Unsurprisingly it sank, proving once

again that you can't have your kayak

and heat it too."

VCP Avocet, Aqua

NDK Explorer, White on White

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The other day while my car was getting an oil change, I sat in a nearby park and played with my GPS. I had a good view of the sky and was receiving from six satellites. And although I was perfectly stationary, sitting on a park bench, the altitude was constantly fluctuating. It went as low as 6 ft and as high as 65 ft. So I guess I shouldn't put too much faith in that reading.

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