Quatre Cocos Beach generally offers safe swimming conditions within its lagoon, with relatively calm waters. However, as it's a more local and less developed beach, there might not be lifeguards present. Always exercise caution, especially with children, and be aware of any boats or local activities. The water is typically clear and inviting, characteristic of Mauritius' east coast.

For good weather and a more tranquil experience at Quatre Cocos Beach, consider visiting during the cooler, drier months from May to December. This period offers pleasant temperatures and less humidity. As it's a local beach, it tends to be less crowded than resort-heavy areas, but weekends might see more local families. Weekdays during this period are ideal for peace.