Ever since my friend Alice took me Geocaching in Arizona, I've been hot on the trail for a GPS. The handy little Garmin Etrex that we used then was fun, but at around a hundred bucks, I thought I'd look into the GPS systems used in cars and trucks. Sure enough, there were several models that were portable enough. I had a list of needs for each purpose to help me choose among them.

First, for geocaching, I had just one need. The unit had to accept longitude/latitude coordinate data as a destination and be able to navigate to it – off road. While the MIO and the TomTom both appeared to accept the coordinates, I'd just have to make purchase and test one to see if it could navigate me to the point. I went with the TomTom because it met my "auto-application" needs better.

Second, for auto-navigation, I had only two needs. 1. Since, I'm often speaking at schools, I'd needed it to list schools in the Point of Interest (POI) category. 2. I liked the multi-routing feature as well. Other than that, I wanted something that could be updated if I needed fresher Maps.

At the time I made purchase, both the MIO and TomTom ONE were on sale, I went with the TT1 for $119 (after a $50 rebate) at Office Depot.

Though the Mio's shape seemed the best in the store, I just love the curved back of the TT1. I took it geocaching the same day I bought it. An hour in my hand, never in the pocket – it felt good. I just like holding it.

Instructions. Surprisingly, they're limited. But, the unit, though it has many options, can be figured out in an hour or less. Just keep tapping all the options and see what it has to offer. I like that. In fact, I found an option that allowed me to choose "walking route" instead of "fastest driving" navigation. But, despite opting for it, the unit still was subject to "Snap to the road" first and only let go of the snap if I walked 50 feet or more from any known street. At that point, the unit switched by itself to its "pedestrian mode." I'll have to experiment more to see if I can find a way to get it to initiate my navigation in that mode. Nonetheless, navigation in that mode still feels imprecise – that also will take more toying. Fortunately, in all my poking around, I stumbled into a screen that displays my actual location in coordinates in real time*. Really, to geocache, I just wanted the unit to display the distance between me and my waypoint. That way, I just walk about until that distance is zero feet – and there I am – ground zero. The TT1 does that – sort of – in the walking route mode, but I wasn't too impressed with the accuracy. So, I sidestepped all the fancy features and just brought up that one screen with actual location coordinates and walked about until they matched my way point. Which meant I had to remember the two coordinates. It wasn't that hard to remember and it was kind of fun, slinking along two axes. The only problem, the real time* I mentioned above, isn't quite exactly real time. There appears to be a 3-8 second delay, so once I get in the ballpark, I have to start walking really slow and even stop and wait for those coord's to stop dancing about. On that same screen there's a graphical display of the 9-12 satellites pulsing info that no doubt determines those coord's. I don't know the tech of it; I'm assuming the unit is calculating averages. (Note: Don't worry about the format of the Coord's -- both the unit and Geocaching.com can convert them to any of the three standard formats. There's even a "mystery" button on the input-coord's page of the TomTom that lets you input them anyway you want. I use DD-MM.mmm)

Anyway, despite the fact that this coordinate method failed to bring me directly to the hidden geocache, it certainly brought me to the ballpark and the real goal – I had fun! I'll need to play with this some more to see if this automobile device can be just as use-able as a handheld sports model. I'm quite hopeful. However, if you're thinking of doing the same thing, here are two big considerations. The TT1 has an internal, nonreplacable lithium battery that lasts about 2.5 hours. For now, for me, I think that's just barely enough. I'm not a big hiker. But, if you're thinking about day hikes … you'll have to figure out how to hook up an external battery. Of a lesser concern, the unit can only charge in the car or through the USB cable to your computer. So charging in the house is inconvenient – I don't want to power up my computer just to charge this unit, or have to leave my computer on, because the unit is not fully charged. Perhaps, I'll find a way to fit the cigarette lighter connector into an AC to 12vtDC transformer. And lastly, no doubt those sports handhelds are far more durable. Still for my applications, 75% road 25%geocaching, I'm very happy that it looks like one $119 unit can do both.

In summary, I'm hopeful, but still need to experiment more to see if that hypothesis will hold up. I'll update this article shortly after that. If you're experimenting with the same idea, and/or, other auto-navigation systems for geocaching – do let me know what works and doesn't work for you. Click contact us (which is me) at the lower end of the left-hand menu. Thanks! Or if you're lazy and don't feel like typing, just leave a message at my always-on any-hour machine: 1-800-767-7186. And if you're a reader, check out my "books and music" at RossAnthony.com. (You can also find a way to email me through Books & Music there.) Go be curious!

Update (the very next day)

Took the TomTom out again after a charge. This time in a mini-van with 3 more adults and two kids. Since we were getting together for brunch anyway, we decided to hunt cache afterward. Everyone had a great time, despite record-breaking heat that day (102F) in the city of Anaheim. Wheww. We sought and found 3 out of 4 caches within a 1 mile radius of the restaurant (TenTen – it was dimsum). I was prepared - I'd printed out info for the caches from geocaching.com prior. Finding caches allowed me to confirm the accuracy of the coordinate method with this TomTom. I don't know if it's worse or better than the handheld sports models, but it's definitely proven itself as worthy. Ground zero on my GPS turned out to be as close as 5 feet from one cache and not farther than 15 feet from another. The remaining cache was so easy, we'd just happened to park the car 10 feet from it and one in my group found the cache before I could switch to coord mode. Which brings me to a new positive for the TomTom. I love the fact that I can just pop in the destination coordinates in the car and beginning rolling (no map printing necessary). The TomTom gives excellent directions to the site of the cache - then after parking, I switch to coordinate hunting. That's fun. Also, the battery power was not a problem – still had 25% power left after 4 nearby geo-hunts. (I was turning the unit off from time to time though.) That said, I did stumble across a potential negative. One of the kids in the group wanted to hold the GPS. This made me very nervous, a drop would certainly shatter the LCD. And since geocaching is such a great learning/teaching event for kids, I think grown-ups should let them hold the tool themselves. For that reason, the rugged sports handhelds have my TomTom beat. Still, I plan to fasten my device into some sort of padded carrying case to make it much more drop friendly. And again, the coordinate method of hunting is a great introduction to 2-D graphing which has plenty of applications, not the least of which kids will necessarily come to know and love in every Algebra class.

Updated Conclusion: I'm quite happy with this unit at that price! I'll be geocaching a lot more!