If I remember correctly, when we told the concierge at our Venice hotel that we wanted to visit Murano, they arranged a pick up in a private water taxi to take us to Murano -- at no cost to us. The water taxi is paid for by the glass blowing factory, which gives you a glass blowing demonstration and then turns you loose in their monstrous shop. I don't know if the travel desk on this ship can make similar arrangements; they probably don't have the established contacts that the local hotels do -- but it couldn't hurt to ask onboard.

-- Eric