It can be as short as 15 minutes or as long as it takes. I know that sounds a little insane but its the islands. You are traveling almost the full length of the island. You need to determine how many cruise ships are in port because traffic will be the major issue. My best advice would be to get of off the cruise ship as quicly as you can run through the shopping area and get a cab before the rest of the people get on the road. Who are you booking your boat trip with? Is it a private charter? The reason I ask is it might be worth the fuel to have them pick you up at Crown Bay Marina if time is an issue. It also may be worth it to arrange a Private taxi ahead of time if it isn't out of the budget. This will avoid extra stops and time along the way but you will have to pay extra for the privilege.
Hope this is help full
Jay

Hello John,

Crown Bay to Sapphire... most popular routes would be through downtown and then there are a couple ways once in town to continue on to Sapphire... would be around 8.5 to 9.5 miles. 30-35 minutes in low/moderate traffic. As Captain Jay mentioned more ships means more traffic, particularly around the cruise docks and in town.

--Islander