NavList:

Speaking of tablets, I recently bought a cheap one for a friend who had been completely illiterate of the Internet (he learned what "LOL" means less than ten days ago). When I say cheap, I mean $39. The prices for these entry-level tablets bounces around, and $59 is probably more typical. That's for a small Android tablet running a 2014 version of the Android OS with cheaper versions of all the usual built-in sensors (camera, accelerometers, etc.) and 8 gigabytes of storage (enough for several full-length movies) and all the usual Internet capabilities via WiFi (no monthly fee --you use your own or public WiFi). And numerical computation is nothing to these devices. You could calculate every number in every table in Bowditch and H.O. 229 in a fraction of a second. Don't you want a supercomputer in the palm of your hand... the world at your fingertips for $39...? I mention this because I know that many NavList members are rapidly being left behind by 21st century technology. It is now cheap to catch up. Sure, there's a learning curve, but tablet prices have plummeted (is Android made of crude oil??!). Take the plunge. Another option: if you can find someone with a smartphone that is less than two years old who is upgrading, see if you can get the old phone and use it as a basic WiFi tablet.

On the smartphone front, at the high end of the market, the latest smartphones have added more sensors. Accelerometers and magnetic compasses and GPS and other positioning technologies have been available for more than five years. Digital gyroscopes and Glonass navigation were added a couple of years ago. And the most recent smartphones also include barometers which, for navigational purposes, can yield equivalent altitudes above sea level (when properly calibrated by local air pressure) accurate to about 10 feet most of the time. Barometers have long been available on handheld GPS receivers to assist with altitude measurement. This usually requires calibration with user-entered pressure at sea level. But on a smartphone, software can query the Internet and get updated local air pressure data eliminating most of the uncertainty in the process.

Frank Reed
ReedNavigation.com
Conanicut Island USA