For those who like to hang out on the boat, it is enough to worry about whether it will run aground. And there is really no way to know this, only work from a chart that shows you what exactly is underneath. But what should people do where there is no such chart? simple – Make your own homemade water depth recorder.
Fortunately, the days of capable seafarers manually deploying sounding lines and measuring bottom depths are gone. [Neumi]The depth sounder uses an off-the-shelf sonar sounder with NMEA or National Marine Electronics Association output. Combining GPS module and Arduino with SD card, the rig can not only track how much water there is underneath it, but also accurately track the location of the measurement point. The whole thing is mounted on an inflatable dinghy, let it slowly walk through the range of a small dock, in and out of corners and crevices. Some Python and matplotlib stitch these data into a sounding map of the port, the details are very good. The chart also takes into account the tides, because the water level changes greatly within the four hours required to collect all the data. See its actual effect in the video after jumping.
It is a cool thing to reveal the mysteries of the deep sea, even if they are not that deep. Want to go a little deeper? We have seen it before.