There is often a guide in the water during snorkeling stops, especially at sites with current or where guests are looking for manta rays. But you should not assume that every swimmer will have a guide immediately beside them for the entire session. On a group boat, one or two guides may be supervising several guests spread over a reef while the captain and boat crew watch from the vessel.
That makes the pre-snorkel briefing important. You should know where the group is going, which direction the current is moving, how far you are allowed to roam, and what signal means it is time to return. At stronger sites, guides may deliberately keep the group tighter. At a calm beach, guests may have more freedom to explore within a defined area.
If you are a weak swimmer, nervous in deep water, or responsible for a child, tell the operator before the trip and again before entering. Ask specifically whether someone can stay with you in the water. A reputable crew would rather know that in advance than discover it after you become uncomfortable. “Guided snorkeling” does not always mean one-on-one supervision, so it is worth being clear about the level of support you need.

