Pete, I honestly don't know how you do it. The fish sound just amazing, I've only snorkled once in my life and couldn't believe how tame fish can be and how they seem to swim up to you and check you out. That was in Western Australia around Rottnest Island, a marine reserve so no fishing and lots of brightly coloured tropical type fish. Your experience sounded incredible too.
Great you had such quality time with your boys but how on earth you will manage to drive your Mum so far is beyond me. Make sure you have lots of breaks and do some stretching along the way. Pointless telling you to take it easy, I realise at this stage "easy" isn't part of your vocabulary.
Please be careful, I know life is to be lived but you don't want to end up bedridden and full of regrets...
Best wishes, golitho