Thanks for all the advice guys, especially Bushdog for your kind offer.
I figured that I would like a mast mounted VHF aerial at some stage so I really need my own equipment, and I can't afford a fancy off-the-shelf climbing system, so I went to Bunnings and did this:
I built a 30 foot ladder in 2 sections out of 70 x 35 mm pine which I bolted together at the pontoon and hoisted using the spinnaker halyard. My friend kept the tension on my harness(using the genoa halyard) as I climbed and she locked the halyard when I was at the masthead and cleated it around the genoa sheet cleats as a safety measure. We used to main halyard and her designer handbag to hoist up and down the tools as required.
It was really safe and easy and cost me about $80. I'll store the ladder sections under the house for the next time I go aloft.