Sennen's Tamar class lifeboat was in action on Monday after a report of people and a dog being blown out to sea in a small dinghy.
The City of London III was launched at 3.33pm on Monday after reports of the small craft in trouble between Porthgwarra and Porthcurno.
A spokesman said: "As lifeboat was approaching Porthgwarra further information suggested the casualty may be off Penberth Cove.
"The Shearwater II, on a wildlife sight-seeing trip out of Penzance, reported locating and recovering the dinghy will all occupants safe; the lifeboat proceeded to the vessel, transferred the two persons and `Indy` the spaniel to the lifeboat, along with the dinghy and returned all to Sennen Cove, arriving at 4.30pm.
Weather:- showers, wind northwesterly force 4 -5 with an increasingly choppy sea offshore.