Party boat rental companies exist in most cities where bodies of water are immediately available. The easiest avenue to find one of these companies is to search local Yellow Pages or another company-listing resource. One big city example is Island Party Boat in Chicago, which rents in Monroe Harbor.
Island Party Boat, like most companies of its kind, offers a number of options that vary in size and prize to fit the needs of any potential boat renter. Consult IslandPartyBoat.com for availability, rates and reservations.
In Florida, nautical renters can visit MiamiBoatCharters.com to view a number of options in the South Beach area.