Thanks for thinking about it. With the present crowd quality and the slack vigilance at Digha, it would be hard to achieve a cleaner coastline. But i know we cannot control the crowd, so we need to make them obey the law. We can also think of Fishing trips into the sea, or maybe cruise trips (not star cruise of course). I am not sure if we have whales or dolphins, if we do then we can start Whale watching or dolphin watching tours, apart from water sports. We can also start renting yachts/boats to well-to-do customers. Apart from the Digha Tourist Lodge, i think WB govt should think of a star category resort and market it properly to attract foreign footfall.
Yes law enforcement is of primary importance. Also we need to have wider roads along the coastline otherwise it would lead to congestion. Plus we need huge marketing efforts like what Kerala and Gujrat Govt did to promote tourism. Moreover if you look at what New York, Disneyland does for marketing efforts.....that is awesome. They rope in specialized 3rd party marketing companies and do special road shows, give advertisements in travel magazines across the globe and ensure that the travellers have a hassle free experience.