"Too bad I don't have any dynamite. That would sure help with the tunnel-digging part." Grin. He always did like to blow things up.

Then he asks, "You could bring air in with a preset spell? I must confess, I have no idea how such a spell would work. And as for the digging, maybe we could find some shovels somewhere in the city. These mer people must have used digging tools to build their buildings and dig out the foundations before they even started. It would be hard work to dig a new tunnel, but I think it could be done."