Now there is a question....
Having been based in the dockyard, I can only speak from my own experience. Being based in Victory Building we had lockers in the actual building, which I believe is the case with most units based in the dockyard. RA lockers in Nelson I honestly have never heard of but I assume there must be somewhere.
Logic being if your RA and working within Nelson there must be somewhere, if your going to work for a unit based in the dockyard you will find they probably have their own arrangements.
Check with Nelson UPO or SR. mess, they will be able to help you