Later that year an Act of Parliament was passed enabling construction of a lighthouse, yet despite pleas for a light arriving almost weekly at the NLB, events proceeded only slowly. It was not until 1834 that Robert Stevenson returned in the company of his son Alan. A painstaking survey made it clear that there was little choice for a location. The single largest area was a rock that measured only at low tide. Readings for wave pressure indicated that any tower would have to withstand forces of . There were suggestions that a tower of cast iron or bronze might be sufficient, but Stevenson senior wrote that "no pecuniary consideration could in my opinion have justified the adoption of an iron lighthouse for Skerryvore." On more than one occasion the surveyors had to warn passing vessels of the danger. A ship from Newcastle, whose charts showed only the main rock some miles away, was boarded near Bo Ruadh. The Master, oblivious to the dangers, was found lying at ease smoking a pipe with his wife beside him knitting stockings.