A fishing vessel with three on board reported that they were drifting 3 miles offshore. They had fouled their propeller but having freed it they were unable to fix the engine in the lowered position. The lifeboat was unable to find the vessel although the visibility was excellent. The NCI at Froward Point were also unable to see any vessel in that position. The casualty vessel then reported to the Coastguard that they had fixed the problem and were returning to port. The lifeboat abandoned their search and returned to station.