gps?

[rick stoehrer]

anyone have much experience using one of these things? specifically the garmin etrex 20?

participated in the casco bay challenge this weekend (it was very foggy up there in the AM) and while i got it to work in a rudimentary way i was never entirely sure what the hell i was doing with the thing. it's my first departure from chart and compass (which frankly you don't have time or space for on a surfski...there isn't even a deck!) and i am having a hard time with the instructions.

and the only map i can see on this thing sorta sucks....it doesn't show ft gorges/hog island ledge at all and that ain't exactly a small thing...surely big enough to give folks like us a refuge if we were in a jamb - took it on a bike ride last night and i can see what i think it refers to as a track...i went around lake gardner and while it shows me making that part of the loop...it doesn't show me a lake on the map/screen? huh? makes me wonder what i am doing wrong and/or what all else won't be showing up on this thing when i might need it.

so far, not clear what i'm doing at all with it.

[spuglisi]

Good thread. I have the same model and similar confusion. I do think that software called"blue chart" can be loaded and it's very detailed for our purposes.

[JohnHuth]

I haven't used a GPS for some time, so I don't know the features on the etrex 20. There *should* be a map that accompanies the display, and there are multiple displays available. For example, you can get a bearing display, an elapsed time/speed/etc display.

In had/have and etrex vista, which is fairly old, but even with the rudimentary maps, got some fairly reliable data. The biggest issue is that the exposure to salt water degraded the receiver.

Typically, I would punch in waypoints ahead of time - points of land, or landing spots. I then would link them together in a path. There's a display that will tell you your heading to a waypoint - distance to waypoint, speed - that kind of thing. When I was using one, I liked to use this feature - but it required that a pre-program in the route I was using.

I tried a side-by-side comparison of the waypoint-traveling with the GPS and a pre-laid out dead reckoning scheme. In the dead reckoning scheme, I had such-and-such paddle strokes for each leg and a magnetic compass heading. I compared that with the GPS waypoint traveling. This was in a thick fog going from NE Harbor out to Little Cranberry. The waypoints tended to only be accurate to about 200m - probably not limited by the GPS itself, but my ability to input features using a map. Map accuracy tends to be worse than the intrinsic resolution of GPS'es.

As it is now, I'm mainly a map and compass guy, even in the fog. Last week in the Jonesport/Machias area, one of the guys I paddled with had a GPS, but we never used it - just stuck to map and compass.

[rick stoehrer]

i'm with you john - i can sort it out just fine with a chart and compass and nothing else...but it takes a skosh of time to do so...and these are races (even though i don't have a chance in hell - holy smokes these people are speedy) and need to concentrate on getting where i am going, fast.

i will look up bluechart, sal and see what it says about getting that done.

now, any suggestions on actually using the damn thing....

thanks

[gyork]

now, any suggestions on actually using the damn thing....

Rick, it sounds like your GPS might not have advanced charting software to enable you to utilize it effectively during a race. In orienteering, participants must begin each race by copying information from the master map, AFTER the clock starts ticking. Are you made aware of the exact course description well ahead of time via a website or other E-notification? If so, you could create a path, as suggested by John, or you could create waypoints, using data from the "master" map. Save each waypoint numerically, in order of race route, then use "waypoint", "select", then "go to" function. After reaching each waypoint, check these off in your brain, as it would otherwise be confusing without a way to verify (hint: with permanent or china marker, pen numbers 1 to X on your boat, and cross them off as you get to them?). This assumes a straight-line route between waypoints, which may not apply to each particular race. Just as mastering chart and compass takes untold hours, so too must be the learning curve for these electronic gadgets that are new to us, unfortunately. Edited July 1, 2013 by gyork

[...]

Rick,

Try accessing YouTube and search using Garmin eTrex 20. There appears to be a boat load of videos for your viewing pleasure.

Warren

[Dave M.]

Rick

Google Earl Backcountry tablet. This is more than a GPS so it may be overkill for your purposes

Dave

[Dave M.]

Rick

Earl's website

Earl Backcountry Survival Tablets

http://www.meetearl.com/#features

[EEL]

John:

"Map accuracy tends to be worse than the intrinsic resolution of GPS'es."

Which suggests you cannot expect such waypoints to put you precisely on a location, but, based on reports on the forum, close enough apparently.

Accuracy of plus or minus 200M could put you off enough not to be able to see the destination in bad fog. I suspect normal error is much smaller.

Ed Lawson

[leong]

anyone have much experience using one of these things? specifically the garmin etrex 20?

Wow, this is a perfect question for Lisa … she uses a GPS regularly, especially for races.

I just took a look at the manual for the Etrex 20 and noticed that it has an electronic compass. I don’t know how to turn that compass off, but I think that that’s important.

Before the race, enter a series of consecutive waypoints (probably the turning points) which are the endpoints of a series of straight-line segments. I don’t think you want to enter the waypoints from the GPSs map, it may not be accurate enough. If possible, paddle the course in advance and enter waypoints by saving your waypoint as your current location.

During the race do a find to each consecutive waypoint; i.e. when you arrive at the first waypoint do a find to the next one, etc.

My GPS has a display that looks like a compass rose with a pointer. To get to a waypoint, I travel in whatever direction that keeps the pointer pointing to the top of the screen. As long as I keep it there I’m traveling a beeline to the waypoint. This pertains no matter how much cross velocity there is due to wind and current (i.e. it’s not necessarily to worry about ferry angles).

I don’t think you want to use the GPSs map in a race, it’s not accurate enough on such a small display and there’s little time to read it.

I’m sure that Lisa will say more, sooner or later.

[bob budd]

Your GPS should be able to place you with an accuracy of 10-15 ft. On the water you should do very well as there are few obstructions to multiple satellites. In urban environments the buildings get in the way and most of today's systems use accelerometers and dead reckon with similar accuracy, though the accuracy will tend to degrade without access to the satellites now and then.

[rick stoehrer]

Downloading a buncha marine charts now (so between $ for those and an expandable micro SD card - about doubles the price...quite a scheme) and we'll see how this goes...whether or not Ft Gorges is "discovered" on there.

[lhunt]

Hi, Rick,

I use my GPS (Garmin 60CSx) for racing. Some of what has been said works, but is too slow for racing. You need something that doesn't require hands :-)

I've never used an eTrex, but I've looked at documentation before to answer questions. Can't tell you in detail, but I'm going to assume that the software is similar to mine, but the screen is smaller. I think that's more or less the case.

Some people have suggested waypoints. Yes, but the thing is, I don't think it will automatically determine that you have passed a waypoint then point you to the next one. So it doesn't work for racing. You're not going to stop and tell it to find the next waypoint.

What I do in the Blackburn Challenge is put in ONE waypoint, at the endpoint of the longest straight leg of the race, and do a FIND on that. I also have loaded into the device a TRACK for the race. I use one from a previous circumnav, so I don't have to worry about map inaccuracies. I like to first edit the track on my computer to remove extra points from the straightaways to save space and to make straight lines where I want straight lines, but it isn't necessary.

The TRACK shows as a curved green line going around the whole course. The FIND shows as a purple line pointing straight at the waypoint.

If I did a race where I had no previous track, I would create the track and the waypoint using Google Earth rather than the Garmin map. The Garmin map I have is not very accurate. Getting from Google Earth into the Garmin requires some cursing, but it can be done. I haven't done it in a while. It required some converters that I found free online. Ask me if you need to do this...

Before the race, I set the zoom level on the map page to something that will work - too far out and you can't see the track if you wander a little, too far in and you can't see any landmarks on the map. Practice it ahead of time and remember the zoom level number.

During the race, if it's foggy, I put up the map page, set to "track up" (not "track north"). As I said, the TRACK shows as a curved green line going around the whole course. The FIND shows as a purple line pointing straight at the waypoint. At the start of the race, the FIND line is not useful yet - it points off to the side at the waypoint. Instead, I point my boat so that the current section of the TRACK on the map points to the top of the screen, and navigate that way. Later, when I start on the longest leg of the race I can look at the FIND line rather than the track. The FIND is better because you always get a pointer from where you are. The problem with the TRACK is that if you get far enough off it it won't show on the map any more. But it's way better than nothing.

In a fog, I look at the map A LOT, to keep on the track. If you lose it, you have to stop and zoom out to figure out whether you need to turn left or right to get back onto the track.

As you may remember from a previous thread, the whole map, track, and waypoint are oriented on the screen relative to your movement, not to how you are pointing. So you can follow the track with confidence in a crosswind or current - it will be giving you the right ferry angle.

Note that if you have preloaded a track, you don't need much map detail. Less is better or the screen gets cluttered. However, you should be able to see the islands. I am using the map TOPO US 2008. This is not a marine chart, but it shows more detail than your default maps. If that isn't enough, you need to buy different maps. Sometimes it has the island but no name for it. You can put waypoints on unnamed islands ahead of time - the names will show up on your map as you paddle.

If the screen on your eTrex is too small to do all of this, and you have an after market dashboard mounted Garmin GPS in your car, you can try to get that to do the job (in a dry case of course). It can probably be set to "off road", and it can probably use the MapSource Trip and Waypoint Manager software that you use to download the track and the waypoint. OK, I admit I never tried this, but I certainly would if I needed something to work with for the next race.

Some general opinions about using a GPS while kayaking:

• As Leon says (or meant to say), if you have a MAGNETIC compass, disable it. I don't think your model does. It probably has a compass page which just shows what direction you are traveling in by taking the difference between your last position a second ago and your position now, and displaying it graphically as though it were a compass. I don't think that's useful. I think if you want a compass on your boat you should have an actual compass.
• My device can show 1, 2, or 3 data fields on the map page. I usually set it up to show speed and trip odometer.
• In my opinion, the only two useful pages are the map and trip computer. Tracks page is useful to manage tracks (delete old ones, etc.), but not while paddling.
• I have given all these notes about Garmin - for all I know all these things are also possible with other brands but I've never tried.

I haven't taken the time to look up the pages that your device can show, and whether you can disable them, etc., the way you can with mine. I'm sure you can experiment with it and extrapolate...

Hope that helps,

Lisa

[lhunt]

Your GPS should be able to place you with an accuracy of 10-15 ft. On the water you should do very well as there are few obstructions to multiple satellites. In urban environments the buildings get in the way and most of today's systems use accelerometers and dead reckon with similar accuracy, though the accuracy will tend to degrade without access to the satellites now and then.

Yeah, the problem is more with the maps than with the GPS.

[lhunt]

Downloading a buncha marine charts now (so between $ for those and an expandable micro SD card - about doubles the price...quite a scheme) and we'll see how this goes...whether or not Ft Gorges is "discovered" on there.

Ouch - probably useful anyway, but I hope my being tardy in posting didn't cost you extra bucks! -Lisa

[rick stoehrer]

Linda -

yes, that's helpful. I may send you an email about getting google map waypoints onto this thing.

[lhunt]

That got a lot easier - found kml2gpx.com. In Google Earth, I created a track and waypoint, like this. I put the track and waypoint into a folder on Google Earth, then extracted that folder (right click, save place as...) as a .kml file. Then, using kml2gpx.com, I converted it to a .gpx file. Now I can load the .gpx file into MapSource, and from there it can go down to the GPS.

The track editing tools in Google Earth are a little fussy, but it's doable. There is an "add path" button at the top of the screen that will let you draw a line. While the "properties" box is up, you can edit the points. Nudging will move a point. Right clicking will delete a point (the trick is to left click on the point you want to remove first). If you want to add points you need to click on a point before the point you want to add, then click on the line where you want the new point.

[gstamer]

I happened to be browsing the forum and came across this thread, I hope you won't mind me joining in...

I use a Garmin GPSMap 78 with BlueChart and Topo maps for expeditions and long races, including the 300 mile Everglades Challenge. As John said, you can setup a route that is a collection of legs (waypoints) and the GPS will route you automatically from one leg to the next, hands free. Although I also add waypoints for strategic locations, I find it most efficient to navigate by one or more routes during a race so I can keep my hands on the paddle, and not waste time pushing buttons on a GPS. Different units have different specifications, the GPSMap78 will allow up to 50 routes with 250 legs (waypoints) per route.

My favorite software for creating and managing routes and waypoints is Garmin's HomePort (approximately $30.00 to download). It takes awhile to learn but has a rich set of features, including optional satellite imagery.

GeoGarage ( http://marine.geogarage.com/ ) is free and has a nice feature to let you overlay satellite and marine chart views, but is awkward for editing long routes. Google earth can be used as well as is very good for reviewing finished routes and ensuring that there is no conflict between charted views and satellite views. This happens quite often in shallow areas that change frequently, such as inlets. If in doubt I usually edit the route to agree with the satellite image.

Greg Stamer

[lhunt]

Hi, Greg, thanks! That's very helpful.

I tried to get my device to move automatically from one route leg to the next and never got it to work. Is there a trick to it? I tried setting "route leg transition" to auto, then tried again with "distance" set to .1 mile (and some bigger values). Was surprised that it never transitioned, but kept doing a find on the first point. User error, no doubt, but if you can set me straight I'd be grateful.

I admit it was a long time ago that I tried it, maybe I just need to try it again now that I've gotten better with the device.

-Lisa

[gstamer]

Hello Lisa,

My GPS is usually set to route transition by "Auto" but I have also played with using the "Distance" option as well. Auto should direct you automatically to the next leg (waypoint) in your route, while Distance requires that you get within a set distance of the current leg before it routes you to the next one.

The difference is whether or not you need to follow the legs (waypoints) very closely. For example, if your route is A - B - C , do you need to pass right over B (and if so, by what distance), or it you miss B, is it OK to proceed on to C without backtracking to pass over B first? That is what the options allow you to fine-tune.

If you need to follow the legs closely, then the distance option can be useful. For example you can set this to be a small distance if you are following a tight channel in shallow water and can't afford to stray a set distance from a leg. However normally on open water, if I stray a little away from one leg, I don't care, I certainly don't want to backtrack and just want the unit to direct me to the next leg. The "Auto" option works fine for that.

I don't know why your route wasn't working for you. It's possible that your route wasn't setup correctly or maybe the route direction was incorrect. For example if your route is setup to take you to A - B - C and you are at C, then it will just keep pointing you toward C. There is an option to "reverse a route" that will fix this.

IMO, some of these features can only be learned by using them, otherwise they seem hopelessly complex when you read about them. What I did to learn routes was to setup a short, simple route around my neighborhood, where I normally walk my dog, and then experimented with what happened with different options (Auto, Distance, etc) as I neared and passed the legs in the route as I walked. Just setting up a small route will be a major victory as you first need to learn the software, view the maps, create a route and download to your GPS.

Best,

Greg Stamer

[lhunt]

Hi, Greg... I'll definitely give it a try again. I tried the same walking thing (also with a dog) but never got it to work. I'm sure I screwed it up somehow, it seems simple when you describe it, and that's how I thought it would work but was unsuccessful. I figured I just misunderstood the feature completely. Now I know better, thanks.

Lisa

[leong]

My GPS is usually set to route transition by "Auto" but I have also played with using the "Distance" option as well. Auto should direct you automatically to the next leg (waypoint) in your route, while Distance requires that you get within a set distance of the current leg before it routes you to the next one.

Options? I wish my Etrex Venture had such options (see http://www8.garmin.com/manuals/eTrexLegendHCx_OwnersManual.pdf for the manual), at least I can’t find the options. That’s why I have to do another “find” to the next waypoint when I arrive at the current waypoint (a little bell sounds at the arrival at a waypoint, which is useless on the water during a race). In fact, creating a route is of no use to me unless I want to use the map page, but that’s too small for me to see. Instead, I use the so-called “Compass Page” shown on page 23 of the manual.

Any ideas about how I can get this GPS to jump to the next waypoint automatically (based on distance or anything) when I’m following a route using the “Compass Page”?

-Leon

PS

What class did you compete in for the Watertribe Everglades Challenge. I’m thinking of paddling the 70-mile ultra marathon next time.

[lhunt]

...Any ideas about how I can get this GPS to jump to the next waypoint automatically (based on distance or anything) when I’m following a route using the “Compass Page”?

On pg 25, it says "press menu twice > routes, select a saved route > navigate".

On pg. 26, it looks like you only have the "manual" or "distance" options.

This is pretty much how mine works, but it has a third option "auto".

"Distance" would probably work - you could put in .3 miles and when you come within .3 miles of the current waypoint it would automatically do a find on the next waypoint.

Dunno what it shows on the compass page. I think it's meant to work with the map page.

-Lisa

Edited July 3, 2013 by LHuntington

[gstamer]

Leon,

I had an Etrex as my first GPS, but I had problems with the small screen and using the joystick through a waterproof bag. I'm much happier with the GPSMap 78 series. For serious stuff, I carry two of them.

I entered as class 2 in the Everglades Challenge, but could have entered either class 1 or class 2 as I was using an Epic 18X without a sail. Next year, I might try class one with the same rig as there are more entrants in that class.

Best,

Greg

[leong]

Leon,

I had an Etrex as my first GPS, but I had problems with the small screen and using the joystick through a waterproof bag. I'm much happier with the GPSMap 78 series. For serious stuff, I carry two of them.

I entered as class 2 in the Everglades Challenge, but could have entered either class 1 or class 2 as I was using an Epic 18X without a sail. Next year, I might try class one with the same rig as there are more entrants in that class.

Best,

Greg

Thanks, Greg

Actually, according to the rules (that I found), the length to beam ratio for class 1 cannot be more than 10.99 (I assume that means at the 4-inch waterline as per Sound Rower’s rules). That rule knocks out the Epic 18X for class 1, but not the 18X Sport. I have an 18X (actually the Ultra lay-up) and a QCC700X. Or do they make an exception for the 18X because it’s really not a high-performance racing kayak like the West Side T-Rex?

-Leon