Safety · Destination Guide

Sesimbra

Atlantic reef and wreck adventures on Lisbon's wild side

Safety And Conservation

Sesimbra diving is safe and rewarding when treated as an Atlantic environment: plan for swell, use surface signaling, and let local operators choose the right site for the day. Conservation is central because much of the coastline sits inside a managed marine protected area.

Top Risks

Primary risk: Atlantic swell and surge
Secondary risk: Cold water and thermoclines
Emergency contact: 112 (112)
Safety overview: Sesimbra diving is safe and rewarding when treated as an Atlantic environment: plan for swell, use surface signaling, and let local operators choose the right site for the day.

Dive safety

Before You Splash

Check swell and wind, not just sunshine. A calm harbor can hide rough water outside.
Choose exposure protection for cooler water and potential thermoclines.
Brief the ascent plan: deploy an SMB when needed and stay tight to your buddy.

In the Water

Expect surge near rock and wreck structure.
Avoid contact with the bottom. Kelp and invertebrates are fragile.
Be aware of fishing line and boat traffic.

After the Dive

Hydrate and keep warm. Wind chill on boats is a common fatigue factor.
If you suspect decompression illness, treat it as an emergency and call 112.

Portugal's national emergency number is 112. For non-urgent medical advice, Portugal also operates the SNS 24 health line.

For any serious diving injury or suspected decompression illness: call 112 immediately.
For health guidance when it is not an emergency: call SNS 24.
For incidents at sea or in port areas: contact the Maritime Police.

Snorkel and freedive safety

Atlantic swell and surge
Exposed sites near Cabo Espichel can have surge even on days that look calm in the harbor. If the forecast is borderline, choose sheltered-bay dives instead.
Cold water and thermoclines
Upwelling can make summer water feel colder than expected. Pack exposure protection and do not underestimate wind chill on the boat.
Fishing gear on reefs
Some areas have fishing activity. Carry a compact line cutter and maintain good buddy spacing, especially in low visibility.
Boat traffic near the harbor and popular coves
Use an SMB on ascents and a float/flag for snorkel and freedive sessions. Avoid swimming across obvious navigation lanes.

Wildlife and protected areas

The Professor Luiz Saldanha Marine Park (inside Arrabida Natural Park) uses protection zones to balance conservation with sustainable use. Recreational activities like diving are allowed, but rules vary by zone and organized groups can require permission.

Follow buoyancy-first diving. Do not touch, feed, or collect.
Support operators who use approved moorings or environmentally friendly buoy systems rather than anchoring on sensitive habitat.
Keep wildlife interactions passive: observe, photograph, and move on.

Do Not Do This

Avoid entering when atlantic swell and surge. Confirm local briefings before committing.

Emergency contacts

Contact	Role	Phone	Availability
112	National emergency number (medical, fire, police)	112	24/7
SNS 24	Health advice line	808 24 24 24	24/7
Maritime Police (Lisbon Local Command)	Maritime police contacts listed by Port of Lisbon Authority	918 498 025 / 210 911 149	On duty
SEPNA SOS Ambiente	Environmental incident reporting line	808 200 520	On duty

Contact

Role

Phone

Availability

112

National emergency number (medical, fire, police)

112

24/7

SNS 24

Health advice line

808 24 24 24

24/7

Maritime Police (Lisbon Local Command)

Maritime police contacts listed by Port of Lisbon Authority

918 498 025 / 210 911 149

On duty

SEPNA SOS Ambiente

Environmental incident reporting line

808 200 520

On duty