I noticed the zinc anode located on the bow rear area is due for a replacement. Any recommendations what to use? It seems to be a circular one - but what diameter and thickness?
Also: are there other anodes, on the prop/sail drive and the rudder?
There's an anode on the saildrive leg and if you have an articulated propeller, on there too (depending on the model of prop).
I'll go and make a dive to check. But: What is an "articulated" prop, please?
There will be a split anode on your 130 saildrive leg. standard item freely available. However if you have an Ambassador stripper rope cutter you will need the modified version. A Volvo fixed blade aluminium propeller does not have an anode but most folding or feathering propellers do and you need to check the make as the anodes are specific to the propeller. The hull anode is not critical as it is the ground for the shorepower circuit. They have fitted various type and they are odd sizes in my experience. If you have a bow thruster there will be an anode in there as well.