You may have noticed from yesterday’s email that while modern chartplotters offer a wide array of features, to really get the most from them, there are also a lot of add ons available.
Probably the single most useful add on is a depth finder. Knowing the depth can keep you from running aground, but it can also help you confirm that you are where the chartplotter says you are. If the chartplotter says you should have 100 ft of depth, but your depthfinder says you have 20 ft, you really should stop and figure out what is going on! While bigger boats tend to have these installed as a thru hull, you can also get ones capable of shooting through the hull itself (depending on the material of the hull!), ones that attach to the transom, or these days even a handheld point and shoot style.
For sailors, and for those interested in learning how to really dial in your predictions for time/speed/distance, another very useful instrument is the anemometer. That is, a wind instrument. These days, that is also available as a handheld instrument, or a device that plugs into your smartphone. Sailors in particular need to be aware that wind speeds increase as you get above the water, so if you are using a handheld instrument, it might not be very accurate for what your sails are experiencing. Whether or not you have a wind measuring device, it is still ideal to learn the Beaufort scale, so that you can judge wind speeds based on what the water around you is doing. This will also help you avoid surprise gusts or squalls, as these often leave traces in the water or can be anticipated by changing wind direction.
The other instrument I mentioned yesterday was AIS, but I think that is an important enough subject to leave for its very own topic tomorrow.
Keep safe, keep learning