Hi,

It would be nice if any of you who have first hand experience with using the different android-alternatives could share your experiences.

I used topodroid for the first time this year. It was our first time paperless surveying, so I can't compare it with pockettopo, sexytopo or any of the other options, but compared with paper I thought it was pretty good and I'd be keen to use it again. We bought a cheap new android tablet, a 7 inch Huawei Mediapad for NZ$119. This isn't waterproof so we bought a plastic lunch-box to transport it through the cave, and a waterproof bag for use while surveying. The 7 inch screen was plenty big enough, and great for surveying walking size passage, but annoyingly big for SRT and crawling-size (or smaller) passages. I think 4.5 and 5 inch android phones are a similar price and would tuck inside your oversuit more easily, and given you can zoom in and out, I suspect they'll be big enough to use topodroid. The waterproof bag worked fine in dry and drippy caves, as long as you squeezed the air out before sealing it. In wetter passages (which were fortunately rare) once the bag got wet on the outside it was much harder for topodroid to recognise my drawing. I also found that I usually couldn't wear gloves, so ended up with very cold hands surveying. I suspect fingerless gloves would easily solve this, but I was reluctant to cut my gloves mid-expedition! Battery life seemed to be fine, and it would last multiple surveying trips. I didn't find topodroid too hard to learn to use, and I'm really not a geek (as my past mails to this list prove!). We did have a bit of a learning curve to start with, but that was partly to do with us getting used to the workflow of paperless surveying, and me learning how to do notes (I've typically done instruments in the past). That is not to say that there isn't room for improvement in topodroid, and I hope sure it will evolve and improve over time. My two biggest criticisms were: 1. In the end I found it most efficient to export the data in survex format and the sketches as pngs (higher res would be better), then re-drew them in therion. I know you can bring the drawings into therion directly, but I would spend longer joining line-wall segments, flipping them the right way round and smoothing them. 2. It is a shame that you can't see the rest of the cave (even if it was just the centerline), just the survey you are in. At least you can open up different surveys to check things, but it woudl eb nice to see where other passage was in relation to your current survey. There are a few other more minor things that could be better (e.g. rotating air and water flow arrows is clunky, cross sections are annoying, some of the icons are misleading etc) but these aren't a big deal. Thanks, Jenny