A Perth fisherman who was left stranded when his boat capsized off the Ocean Reef coast on Sunday afternoon was stuck at sea for over four hours before he was able to alert authorities.

Lindsay Lankester set off from Ocean Reef Marina about 5pm on Sunday intending to soak his craypots, and was returning home about 6pm when his boat hit reef and was swamped by a wave.

Mr Lankester was thrown from the boat as it capsized, and said his situation became increasingly more desperate when he realised his EPIRB was trapped in a compartment on the boat.

Mr Lankester said he repeatedly dived to try and free it from the boat without luck.