noon
We were far out on the broad Pentland Firth , plunging about on the rough water , with our mainsail double-reefed , and the flying jib pulling away like to split itself in the wind . I enjoyed it all for a time ; but when I went below to help Jerry to get ready some breakfast for the skipper , the smell of the coffee and the frying bacon overcame me , and I was forced to go back to my bunk , where I remained for the rest of the day helplessly seasick . The next morning , feeling better , I went up to get a breath of fresh air , and found that we were hemmed in by a thick white mist that crept round us , and rendered it difficult for Jerry , who was on the lookout at the bow , to determine our course . We were making for South Ronaldsay , and had been beating about all night , making very little headway ; and when the mist lifted before noon , it was discovered that we had been driven down by the current , and had come nigh to running into the black rocks of Stroma Island . Here , where two strong streams met with terrific force , the turbulent water whirled about with wild irregular motion , and we were swept now one way , now another , until it seemed useless to fight against the current that controlled us . We were , in fact , in the midst of that dangerous vortex locally known as the Swelkie . Those who know the secrets of the ocean currents of the northern seas have their own scientific explanations to give ; but our native boatmen and sailors , who were not so well acquainted with the eccentricities of the Gulf stream as with the popular legends of Orkney , accounted for the Swelkie in this way : A certain King Frodi had a magical quern , or hand mill , called Grotti ; the largest quern ever known in Denmark .