Pedra da Nau
A sheltered bay off Cascais named for its central rock, sand giving way to rock cutwork with sea bass; an easy dive close to the marina.
Last updated September 2026
The dive
Pedra da Nau takes its name from the rock at its centre, the "Nau" (ship), with cormorants often lined up on its highest point as you surface. The dive opens over a sheltered, sand-floored bay to the east, then thickens with rock the closer you get to the Nau: large blocks, holes and cracks where sea bass shelter. West of the rock the terrain runs rougher and more cut; east of it, calmer and more even, so a guide can shape the same dive two different ways from one entry point. Depth reports for the site vary widely between sources (see the depth FAQ for the full breakdown), so plan around the widest sensible range, 4 to 18m, not one settled number, and expect a shallow, sheltered profile whichever figure holds on the day.
What makes it special
A beginner's bay before anything else: every catalogue that names Pedra da Nau calls it easy, and the shallow sand approach means new divers are comfortable before the rock even starts. What holds interest beyond the entry level is the cutwork itself. The holes and cracks thicken as you near the Nau, concentrating sea bass in a way the open sand never does, and the option to swing west into rougher ground gives a certified diver something to come back for. It sits about ten minutes out from Cascais marina, in front of the Hotel Villa Italia, close enough to work as a second dive on the same boat day.
Know before you go
Access is normally by boat from Cascais marina; some catalogues also describe a walk-in approach, though only the boat route is corroborated on this stretch of coast (see FAQ) unless a local operator says otherwise. No marine reserve, permit or diver fee applies here. Reported depths vary between sources here (see the depth FAQ), so confirm the planned depth with your guide before descending if you're freshly Open Water certified. Water sits around 17-21C in summer and drops to roughly 14C in winter, once reported as low as 10C: a 5mm suit covers the warm months, a 7mm semi-dry with hood and gloves the cold ones.
Why Dive Pedra da Nau
What makes this dive site stand out.
- Two-part sand-to-rock profile
Sheltered sandy bay gives way to dense rock and holes near the central Nau rock
- Sea bass in the cutwork
Rock holes and cracks near the Nau shelter sea bass, the site's signature sighting
- Short boat ride from Cascais
About ten minutes by boat from Cascais marina, in front of Hotel Villa Italia
- Contested depth range
Reported maximum ranges from 11 to 18m; treat 4-18m as the outer envelope
Depth & Profile
Location
38.6894°N, 9.4255°W
Conditions & difficulty
One source names this as the calmer window here, with lower swells; the wider area's own calibration favours autumn instead, and the two are not reconciled.
Every source frames the site as beginner-friendly, but depth reports disagree sharply (see the depth FAQ for the full range); at the disputed upper end the dive sits right at the Open Water ceiling, not comfortably within it, so confirm the day's planned depth before booking.
Rated beginner-friendly across catalogue listings; the rock cutwork near the Nau adds interest for more experienced divers too.
Marine Life
Rules and permits
Frequently Asked Questions
How deep is Pedra da Nau?▾
Depth reports disagree sharply: one listing gives a 14m maximum, another 18m, a third caps the site at 11m. Plan around the widest sensible range, 4 to 18m, not one settled figure, and confirm the maximum with your guide on the day.
What certification do I need for Pedra da Nau?▾
Open Water is enough for the site as it's usually run: it's marketed as beginner-friendly and most reported depths sit inside that ceiling. Because the upper end of the depth range is disputed (see the depth FAQ) and sits right at the Open Water limit, not comfortably within it, ask your operator to confirm the maximum depth they plan for the day, especially if you're newly certified.
Is Pedra da Nau inside a marine reserve?▾
No. No marine reserve, park or protected-diving designation covers this bay or the wider Cascais coast, and no permit, fee or diver quota applies here.
Can you reach Pedra da Nau from shore?▾
Two catalogue descriptions say the bay is also reachable on foot, but that isn't corroborated elsewhere on this coast, where the other named sites nearby are boat-only. If a shore dive matters to your plans, ask the operator directly where the entry point is and what the walk-in involves before you rely on it, since no operator's own materials describe a land approach here.
Which dive centre runs trips to Pedra da Nau?▾
A third-party dive-travel listing links this site to one of the Cascais dive centres, but that link doesn't come from the centre's own materials, which don't name Pedra da Nau specifically among their dives. No operator is confirmed for this site beyond that indirect link, so confirm directly with the Cascais dive centres that it's on their current itinerary before booking.
When is the best time to dive Pedra da Nau?▾
One source names spring and summer, when swells are lower, as the best window here, though the wider area's own calibration points to autumn as the calmer season instead; neither claim is confirmed at site level, so treat it as unsettled, not a fixed rule. Water runs around 17-21C at the surface in summer and drops to roughly 14C in winter, once reported as low as 10C, so a 5mm suit covers the warm months and a 7mm semi-dry with hood and gloves the cold ones.
Where exactly is Pedra da Nau?▾
The bay sits on the Cascais seafront in front of the Hotel Villa Italia, roughly a ten-minute boat ride from Cascais marina. The published coordinates are approximate, not an exact GPS fix, so use the hotel as your landmark and confirm the run with your boat crew.
Every dive has a story. Share yours.
Log your dives - notes, photos, conditions and the marine life you saw - and share them as one public diver profile. What you share helps the next diver, too.
Log every detail
Depth, duration, conditions, gear, buddy, notes — all in one place. Import from Suunto and other dive computers.
Track marine life
Record species sightings on each dive. Build a personal catalogue of everything you've seen underwater.
Your public dive profile
Share your dive history, stats, and experiences with a profile page you control. Show the world where you've been.