I've conveyed the scheduling realities to my companion and I think the rushed nature of the day-trip concept is beginning to properly sink in. I agree that a day trip in the main area would definitely be a possibility (albeit still not the best of ideas) but the lengthy round trip to the aquarium is, as joejones illustrated so well, barely enough time to properly appreciate things.
We will be re-examining our options as well as the recommended mainland aquariums but I wanted to thank everyone for their help and insight!