Barreta d'en Serra

Roll back into 16 to 18 metres on the Blaumar profile and the bottom comes up fast. The barreta is a thin band of rock running roughly parallel to the coast, narrower and lower than the neighbouring Barra de l'Arbre one row over. The dive resolves into a slow patrol of the cracks on the current-exposed flank: peregrina and flabellina nudibranchs cluster on the upcurrent rocks where hydroid prey is exposed to flow, and a macro lens is the right call for the typical Row 4 dive here. Common octopus turn up between rock outcrops working the gravel; a 2012 owner dive recorded one taking a scorpionfish-sized prey on a single immersion.

Currents are sporadic but real. A July 2008 dive at this site put the diver in a notable south-west to north-east current at 20 metres on the deeper Row 4 band, and the same dive produced a one-off summer event worth flagging: a mass spawning of holothurians and three urchin species, with abalone visible in daylight. That was a once-only observation rather than a reliable annual draw, but it is the kind of thing this site can produce on a July day with the right conditions. Visibility on a calm summer day runs the area-typical 10 to 15 metres, occasionally cleaner; winter post-rain can drop to 1 to 5 at any Maresme site, this one included.

Barreta d'en Serra is the quieter Row 4 option. Centres pick it when they want a shorter, shallower outing on the same stratigraphic band as the busier Barra de l'Arbre, and the 16 to 18 metre operating profile keeps the dive comfortable on no-deco time without giving up the crevice fauna that defines this stretch of coast. The current-exposed flank is what sets it apart: the upcurrent face of the ridge concentrates nudibranch density on hydroid-bearing rock in a way the more sheltered neighbouring sites do not. The local-genitive name signals a working fisherman's spot rather than a marketed destination, and the site has surfaced only once in published first-person community accounts that name it verbatim.

Summer dives need a current plan even on calm forecasts. The standard Mataro convention applies: descend at the anchor, follow the ridge with the current at your back on the outbound leg only if you have planned the return, and carry an SMB for safety-stop ascent if the line has drifted. Compass and dive light belong on every dive here. The barreta is the only feature; the sand on both flanks has no orientation cues. Pick the suit for the deepest part of the dive. The summer thermocline can drop bottom temperature into the 15 to 18 band below 18 to 20 metres even on a 22-degree surface day, so a 5mm with hood is the working summer baseline on the deeper end of the profile. There is no permit, no fee, no concession, and no marine reserve regime at this site.