The Irish Cruising Club guide and Reed's Almanac are essential daily reading on this coast, as the on- and offshore tides are severe and sometimes unexpected.  From Glenarm the northgoing tide is again the ebb from Belfast HW, and if you miss that you are basically up the well-known creek without one.  On this particular leg, rates of up to 4.5knots can be encountered, particularly around the headlands (Torr Point and Fair Head) and are accompanied by severe overfalls, which you can only avoid by going several miles out into the North Channel, the policy adopted by Juggler, who were also travelling north today.  We made a careful plan, and it worked like a charm, though if I were doing it again I would have gone about a mile further out to avoid what proved to be like the Rocky Road to Dublin at some points, with poor old Vega bouncing around like a bucking bronco.  Leaving at 0630, we reached speeds of 10.5knots over the ground with the tide behind us, and were approaching the notorious Rathlin Sound by 0800.  Inside the Sound the tide changes by the hour, swirling around every which way, all documented in the books, so you have to hit it just right, which we did, with only half a knot against us on the last mile of approach to the harbour.  We couldn't raise the HM by VHF or by mobile (it turned out he had it on silent mode), so we crept into the small harbour and came alongside the hammerhead with a difficult side wind, and walked up to the marina office, where we were given the codes, shown the facilities, and directed to a permanent berth.  The office and facilities are all brand new, so much so that they haven't got round to putting in the coin slots for the laundry yet, so we earmarked this to make use of the free wash before we leave!