It’s long been known that one of the biggest drains on the Savannah International Trade and Convention Center’s annual budget is the Savannah Belles, the water transit system that ferries tourists, convention visitors, employees and hotel guests across the river to Hutchinson Island. What may not be as known is the importance of that transit system to businesses on both sides of the river. Consider the numbers: • 631,322 riders a year — or 1,750 per day.