Layer one: who may own
The foundational restriction is on the buyer, not the beach. Cuban home ownership and sale, opened up by Decreto-Ley 288 of 2011, is for Cuban citizens and permanent residents. A non-resident foreigner is outside this market by default, so the very first layer already excludes most would-be beach buyers before location even matters.
This is the layer people most often overlook, because in many countries a foreigner's money is welcome anywhere. In Cuba the question is not how much you can pay but what your legal status is, and a visitor's status does not include a right to buy a residential home, whether it faces the sea or a side street.
Layer two: state land and tourism
The second layer is the state's dominant role in prime coastal and resort areas. Much beach-zone land is state-held or state-controlled, and development runs through approved projects and joint ventures. Foreign capital can enter only via Ley 118 of 2014 within those approved structures, which is a restriction on the form of participation, not just its existence.
Private personal ownership is simply not the mechanism on offer in these zones. Even where a foreigner is lawfully involved through an approved development, that involvement is an investment within a defined structure, subject to approval and partnership, and it should never be mistaken for holding personal title to a seaside apartment on an open market.
Layer three: the shoreline and the US overlay
A third layer protects the shoreline itself as a public and environmental coastal zone, so the idea of a privately enclosed 'own beach' does not match how Cuba manages its coast. Whatever happens with buildings set back from the water, the immediate shore is not a thing a private party fences off and controls.
On top of all this, US persons carry a further overlay: OFAC's 31 CFR Part 515 and Helms-Burton Title III restrict and endanger property dealings regardless of Cuban rules. Stacked together, these layers, buyer status, state-controlled resort land, the protected shoreline, and for Americans the US sanctions regime, explain why beachfront ownership in Cuba is so tightly bounded, and why realistic plans lean toward renting or genuine residency.