There should be just about enough time for your Mum to drive from Bayswater to the Downtown car park (approx 30 mins) then walk to the Viaduct (5 mins) and find the right place to watch you. I would recommend that she drops you off and then jumps in the car, as there will probably be a few people doing the same thing. Once you get to the start, there will be lots of people and most of us are pretty friendly and will help you. Enjoy the swim!

If you are in Auckland the day before, I suggest going over to Bayswater (Note new starting point)and walk out on the end of the marina (I don't know if there are gates to get through or not) From there, pick two large landmarks, eg, Sky Tower and the Hilton Hotel (a white block building just to the left of the viaduct harbour entrance) and use the relationship between these two to guide you during the swim. Any tide effect should be very small during the swim so just go straight. Then drive back to the Viaduct, make sure you know the way, there is a Wilson's carpark, also the "Downtown" carpark, which is possibly nearer the finish. Check out where the finish pontoon is. You won't have time to get lost on the day. Have a great day.