If the All Aboard time at Juneau is 4.30pm, does this mean we have until then to get back to the ship? I've heard somewhere that you have to be back an hour before? I ask because our Juneau excursion drops us at Mendenhall Glacier at 2.00pm. We want to spend some time there before getting a taxi back to the ship. I'm thinking if we leave the glacier visitor centre no later than 3.30pm, we should be back to the ship by 4.00pm. Does this sound realistic? If not, I would rather switch to the earlier excursion than worry about missing the ship! Thanks!