these telltales don’t tell tales

An interesting innovation for offshore sailing comes from France, where digital technology is married to one of oldest tools in performance sailing: telltales. With this clever product from Mer Agitée, the offshore sailor can remain in perfect trim in any wind and sea conditions.
In an age where nearly everything is digitized, one would have thought that the simple act of steering the boat and trimming the sails to the guidance of telltales would remain an analogue activity. We were taught as young sailors to adjust our trim and/or our course to where these simple indicators of laminar flow over the sail membranes were streaming straight aft with no dancing or stalling, and we’ve been trained to use this a priori knowledge for steering and trimming ever since.
There are problems with this simple approach: you can’t see telltales at night without a high-powered torch, and even in daylight, some boats are so large and their rigs so high that the small yarns or ribbons are just not visible from the deck or cockpit.
Now Dimitri Voisin and his team in France have devised an elegant digital solution for this problem called TrimControl, and yes, these are digital telltales. But how is this possible? Read on.