The Selsey inshore lifeboat was launched in the early hours of yesterday morning to investigate lights in the sea off Bognor.
A spokesman confirmed the D class inshore lifeboat (ILB) Betty and Thomas Moore was launched at 1257am at the request of the UK Coastguard after a fisherman, angling on the beach, reported seeing lights in the water to the west of Bognor Pier.
They added: "After launching with a crew of three volunteers the ILB made best speed to the area and after arriving on scene the fisherman reported that a person had come ashore
wearing a wetsuit and said he and one other person were free diving (diving without cylinders). He said his buddy had come ashore further west and they were both ok.
"The divers were Polish and dive all the time usually in the water for up to five hours they were very well kitted out including very good wrist lights which the ILB crew first
thought were Coastguards on the beach searching. They were very apologetic for the lifeboat being launched."
The lifeboat was released by the Coastguards and returned to station at 1.45am, the crew was made up of Helmsman Dave Lamdin, Colin Pullenger and Kristina Dolan.