Below some solutions, experiences, etc that may be useful for others. Comments welcome!
Click on photos to enlarge, right click to download.
Surveillance cameras in aft stay
Monitor status remotely and be alerted when there is activity on or around the boat while moored or at anchor by using multiple Arlo Ultra 2 cameras. Infrared light for night views. Two cameras mounted in the aft stay and can also be used for sailing videos. Batteries last one month or more depending on how frequent videos are taken. Batteries charged via magnetic waterproof clip-on connector/cable.
Barber
haulers for code and downwind sails
Use existing spinnaker boom downhaul (black line on photos) or a dedicated line (if downhaul is already used for the spin boom). Connect with soft shackle to the double ended (grey) dyneema on deck which goes to snatch blocks on each side of the boat.
See them used in our Youtube video.
Fuel volume/gauge measurement
Pump out fuel via the engine fuel hose connection. Fill up in order to see how real volume corresponds to the gauge. Tank capacity 250 liters according to Xc 42 specification. Max 200 liters can be used in reality...
Cockpit net to keep birds out
Also birds like our cockpit behind the window/sprayhood, sitting on the table and steering wheels and shitting big loads.
We solved it with this net.
