I purchased a Raymarine ‘Lifetag’ system, which hopefully improves safety for one-up passages or when pets/children are on board.
A small base station is hooked in to the Seatalk network and polls a couple of tags at short intervals to make sure they are still within range. If the base station does not hear from a tag, an audible alarm starts, and a man overboard (MOB) alert is sent to the chartplotter.
This baby displays all sorts of data, and keeps a short history of data and can display graphs over time.
I intend mounting this in the main sleeping cabin.