Thanks for your input. At this time I'm not sure what runs on 110v and what runs on 12v. The boat has a 2.5 kw inverter installed so I guess that it may be so that the only use for the SP is a charger to keep the batteries up. If that is so then one could assume that all the lights etc are 12v and the inverter is there to power appliances like microwaves, hairdryers, computers etc.
In that case it's a doddle and only the charger needs changing to a 220v one. The thing that flies in the face of the above is that the boat is littered with 110v receptacles but once again, I'm assuming they are all wired to the inverter.
Gil, thanks also for you input. I just wasn't too sure of the switches etc but as said, lower amps has to be good news.
SD ditto your advice. I'm not sure of the 3 vs 4 wires. AFAIK
the 3 wires in NZ are a live, a neutral and an earth. I must confess to never having heard of twin 120v circuits and I grew up in South Africa with 220 - 240v which has the same setup as NZ.
Each circuit in domestic applications here in NZ only has one breaker or fuse holder so twin wiring is not evident. Interesting. What would the 4 wires in the US carry with 110v? Is the extra one to spread the amperage, perhaps?
Hey thanks again guys, I feel a whole lot more comfortable about the thing now. And Bill, if you want to see NZ, take a trip, you won't be sorry. God's own country, this.