Hey guys
It is a long time since you discussed this issue. Sometimes, even with a good heavy anchor and proper anchoring techniques, I never feel entirely safe to sleep overnight w/out checking a few times if I am still in the same position. Any app that you will use will refer to the position of your boat and not the anchor. Using the Raymarine system is heavy on batteries.
Recently, I found a system (From Europe) that connects an anchor to the floating buoy above the anchor. If the anchor moves, then the buoy moves. It has a springing mechanism to compensate for tides up to 5 m on the 10 m depth. It uses a dedicated transmitter and receiver system based on LoRa, so you do not rely on your cellphone. If the anchor moves within a 5 m radius (geofencing), an alert is sent to the receiver on board, letting you know that you are dragging. Looks good, but the price is around EUR 1000 and there is a 3 m waiting time for delivery.
Few years ago I was thinking about putting together something like this, planning to use parts readily available on the market (mainly Alibaba). An extendable cloth line was converted into the link between the buoy and anchor. Antitheft devices/trackers were checked. Most of them are good at tracking stolen devices (will show you the town in Nigeria where your car is taken apart) but not very good at geo-fencing. I wanted to have an alert in case the tracker moved, say, outside a 10 m radius. Most will work only with a cellphone and will need a SIM card. On the water, we do not always have a cellular network. LoRa could be the solution, but how to get the alert signal out of the tracker on the buoy to the receiver on board?
Recently, I found a dog training collar that sends a mild shock to the dog's collar if the animal moves outside of the set geofence. Now I'm looking at how to get the shock signal converted into an alert that could be sent to the receiver on board. The interesting part is that the whole system will cost only CAD 200 if Alibaba comes to the rescue. And an additional advantage: if the anchor is stuck at the bottom, I will have a tripping line!/ik
