Discount rates and property taxes make it relatively infeasible to buy that land and turn a risk-adjusted profit - especially since the margin for error is so slim (a few hundred horizontal feet one way, your properties are a 100% loss, a few hundred feet the other way, you lose much of the waterfront premium). Compared to investing in a stock index at 5%+, the idea is nowhere near worthwhile; you need to find land which would at least double or triple in value just to try to profit at 10-20 years out, and even more if you are planning 20+ or taking into account the carrying costs & risk.