Hi,
you can book online your water taxi. The link is
www.motoscafivenezia.it/english/english.htm
The Consorzio Motoscafi Venezia has a stop at the statione marittima (Marittima Cruise Terminal)
You can also get information by mail. Therefore contact:
info@motoscafivenezia.it
or fone +39 041 522 2303.
Watertaxis in Venice are not cheap, but not as expensive as you marked.
Have a nice trip to Europe an much fun in one of the most beautiful citys in the world (ma favorite city!)
There is also a shuttle bus form the cruise terminal to Piazza de Roma, every 15 to 20 Minutes. Service should be free of charge to passengers.
Best regards
Uwe (from Germany)