Perhaps but a galvanized steel NEMA box will turn into a rust bucket
in no time at all around salt water. I once priced out stainless NEMA
boxes and they go for mucho dinero. Some of the reinforced plastic
boxes seem OK but I haven't seen any big enough for a 12 KVA
transformer.
The other option is an aluminum can. That is what most of the stuff
you see on the utility poles are and most new meter cans are aluminum
here.
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One of the nice things about starboard is the lack of any external
shock hazzard. Also, there's no chance of corrosion and it seems to
be fairly UV resistant. The edges polish up nicely with wet and dry
sand paper.