Yesterday afternoon, about two o'clock, a very serious accident occurred off the Warrenpoint shore.  Several boats had been out in the Pool with some barques at present stationed there, among the the "Maggie A. Fisher" belonging to Mr. Joseph Fisher, Newry.  A westerly wind was blowing, but on their return the latter boat, which had reached the Gongaway Rock, was struck by a sudden and unexpected east puff, with the natural result that she capsized.  There were five men in her, three of whom - J. O'Brien and two brothers named Duffy and Derrigan - got on the keel, and were saved from danger.  Another named Magennis, saved himself by holding on the boat's side.  The other man however, Francis Ruddy - was somehow seerate from the boat, and had to struggle in the water.  Two boats immediately started for the scene of the occurrance - one behind the capsized, belonging to P. O'Neill, manned by P. O'Neill Sen. (owner); P. O'Neill jun.; J. Toal, J. Bradley; the other at the customs House, Warrenpoint, belonging to Patrick O'Hanlon, then crew being Edward O'Hanlon, Ross Parks, Samuel McAlinden, Willaim Parks, James Magenniss, and the master of the barque in the Pool.  All sail was made by O'Neill's boat to come up to the "Maggie A. Fisher".  The sail was immediately lowered in O'Hanlons, and the crew of six fell to the oars with a will and reached the distressed boat a few minutes before O'Neills boat.  The five men were taken on board and lande don the beach.  All were safe, save for the ducking, except poor Ruddy, who was indeed in a dangerous state.  Dr. Ternau was speedily summoned to his aid, and his skill shortly restored the unfortunate man to a conscious condition, when he was carried home in blankets, kindly lent by Madame Ternau.  We ommited to mention that the coastguard boat, Omeath, and the revenue cutter, Warrenpoint, both hastened to the rescue, but arrived too late to be of any use.  Great credit is certainly due to the plucky crews of both O'Neill's and O'Hanlon's boats.  Ruddy died about half past six o'clock last evening.