If you want to know whether or not the tides are high enough to get your sloop out of Ockway Bay in Cape Cod, you could consult NOAA’s tide tables. Trouble is, less’n you’re a pipe-smoking old-timer who’s handy with the lobster cages and a sextant, they’re as likely to get you stuck going in and out of the bay as they are to tell you, with sufficient accuracy, whether the already-shallow draft below your boat is enough to let you safely navigate the muddy shoals of your home port.
That’s where the internet comes in, and not the kind that’s stuck behind a desk, twiddling with an iPad - we’re talking about the Internet of Things. Using an ultrasonic level sensor to bounce sound waves off the sea surface in order to determine its height, an XBee radio to send that data to a receiver on shore, and most importantly, an ioBridge IO-204 to relay that information to servers in the cloud, Cape Cod resident and ioBridge hobbyist Robert Mawrey is able to broadcast to his entire community near real-time data on actual sea level.
The result, shown in solid blue, shows how far off NOAA’s tide estimates, represented with vertical blue hash marks, can be. (Check out real-time updates at the ioBridge tides site.) It’s enough to force a sailor belowdecks to whittle a whalebone for a half hour while he waits for the tide to cooperate, says Hans Scharler, president of software at ioBridge.
More importantly, Mawrey’s sensor, which he completed with the help of the engineers at ioBridge, is just the first of what ioBridge helps will be a world-wide network of hyper-accurate sea level monitors that are all generating their own RSS and XML feeds. These feeds, in turn, can be transformed into everything from maps to SMS updates and Tweets.
Already a second sensor has gone up at Green Pond, also in Cape Cod, and Scharler says that as the network comes up, they’ll be using data from NOAA to fill in the gaps - its accuracy notwithstanding. The sensor at Green Pond is solar-powered, so it only requires maintenance if it goes down. Any community can have one of these sensors for between five and six hundred dollars in parts, says Scharler.
This network might also be of interest to NOAA itself, though Scharler says they are still at the stage where they are letting interested parties come to them, rather than actively seeking partnerships.