In his most recent post, John asks "How much is a boat ramp worth?" Fortunately, there is an amazing paper forthcoming in Marine Resource Economics* that answers exactly that question...for Oahu. The table at the right has the results.
The upshot: the value of a ramp ranges from $.01 to $1.83 per angler per trip on Oahu. This is small because it's an island. If one ramp closes, another is nearby. Closure of a regional set of ramps (5 ramps in close proximity) results in losses of $2.64 to $6.80 per angler per trip depending on the set of ramps.
Do with these numbers what you wish.
*Haab, Hamilton and McConnell, "Small Boat Fishing in Hawaii: A Random Utility Model of Ramp and Ocean Destinations," Forthcoming, Marine Resource Economics.