Posidonia Dive

Posidonia Dive sits at the foot of Port Balis marina in Sant Andreu de Llavaneres, 35 kilometres up the coast from Barcelona. The centre grew from its predecessor Subsiluet around 2012-2013 into an SSI Diamond Instructor Training Center, and the registration number 711345 covers an unusually broad range of SSI authorisations: standard recreational, Mares, Extended Range, rebreather, freediving, Diamond, and instructor training at both recreational and XR levels.

Eight instructors run the full SSI curriculum, from a 60-euro try dive for complete beginners through DiveMaster and professional courses. A free marine conservation course sits alongside the commercial catalogue — an unusual addition that reflects the team's stated interest in ecological awareness. Boat dives cover 24 named sites on the Maresme rocky ridges, with El Santuari, the sunken fish farm, as the flagship. Equipment includes BCDs, regulators, computers, and dry suits; the fill station supplies air and nitrox on site. Rental drops to 50 percent of the standard rate when combined with any course.

The marina location means the Rodalies R1 commuter train from Barcelona stops within walking distance, which several reviewers name as the deciding factor for city-based divers without a car. Facilities include hot water showers, large lockers, a confined water area accessible on foot for pool-stage training, and equipment storage for members of the Hazte Socio programme.

The review body across Google and TripAdvisor totals close to 300 reviews, with a consistent 4.8 out of 5 on Google. Three themes dominate. First, the instructors: Xavi, with over 30 years of experience, Leticia for Open Water teaching, Claudi for beginner work, and Pau for guided dives are each mentioned by name in multiple reviews. Second, El Santuari itself — the barracuda schools and seahorse sightings generate most of the enthusiasm. Third, the train link from Barcelona, which earns repeated mention from international visitors as what made the trip possible without a hire car.

Constructive feedback is concentrated in a small minority. One 2024 TripAdvisor account describes a gas-mixing incident in which an air diver was grouped with nitrox divers, leading to a mandatory decompression stop. A 2025 review describes peak-season preparation as rushed and impersonal. These are outlier experiences in a long review record, but the first carries weight as a safety-relevant incident. Busy summer dates may be worth avoiding for less experienced divers who want closer attention.