The 27-kilometre maritime corridor between Benidorm and Calpe tracks Spain's tallest coastal rock formation, a route Mediterranean traders navigated for centuries before paved highways absorbed the traffic. Peñón de Ifach rises 332 metres from the waterline, its north face sheer enough that rope-access climbers still train there, while the south slope hosts endemic Valencian violets found nowhere else on earth. The coastal shelf between these towns drops from 15 metres to 120 metres within a kilometre of shore, creating thermal layers that draw grouper, octopus, and seasonal tuna migrations. Modern catamaran operators revived this passage in the 1990s when Sierra Helada Natural Park restricted coastal development, preserving limestone coves accessible only by sea. The route passes Altea's whitewashed old quarter perched 70 metres above tide level, its cobalt dome visible 12 kilometres offshore. Archaeological digs near Calpe harbour uncovered Phoenician fish-salting vats from 600 BCE, and Roman anchor stones still rest in 30 metres of water off Morro de Toix promontory. Spanish Civil War bunkers dot the cliffs above Albir beach, concrete observation posts aimed seaward toward supply routes that never materialized. Today's boat trip Benidorm to Calpe tickets grant access to marine reserves where recreational fishing is banned year-round, maintaining visibility that reaches 25 metres on calm mornings. Operators anchor in Granadella cove and Racó del Corb inlet, both too narrow for large vessels, where limestone walls create natural amphitheatres. The Peñón de Ifach tunnel, bored through the rock's base in 1918, channels tidal currents that concentrate plankton and baitfish. Seasonal paella service aboard larger catamarans uses bomba rice from Albufera wetlands 90 kilometres north, cooked in propane-fired paelleras welded to deck rails. Costa Blanca's microclimate produces 320 days of navigable conditions annually, though autumn levante winds can suspend departures when gusts exceed 25 knots. The crossing itself takes 75 to 90 minutes under sail, less with twin diesel engines, and most tours allocate two hours for anchored swimming. DJ-equipped sunset cruises depart Calpe harbour at 18:00 during summer months, timing the return passage to catch alpenglow on Sierra Bernia's ridgeline. Snorkeling excursions to Peñón de Ifach's eastern face reveal vertical gardens of orange cup coral and Posidonia seagrass beds that anchor the sediment, ecosystems protected under EU Natura 2000 designations since 2006.