Said to be the best beach in Jamaica, see beaches.com/blog/seven-mile-beach-negril-jamaica Based on my experience, I would confirm that. Best on the beach near Charela Inn and Couples Swept Away Resort (palm trees, wide beach). If algae are washed ashore, they are also removed there. Unfortunately, there is now also an algal bloom here (like in Mexico, but even more extreme there).
All kinds of water sports are offered. Snorkeling trips are worthwhile, the sea is even more interesting under water, especially if you are in the Caribbean.