Danger of "Pooping a Heavy Sea"

From Sailors and Traders: A Maritime History of the Pacific Peoples, by Alastair Couper (U. Hawai‘i Press, 2009), pp. 33-34:

Long west-to-east voyages, frequently into the prevailing trades, would inevitably involve extended periods of exhausting tacking or reversing lateens, as these vessels could sail no closer than about 75 degrees to the wind. When running free with a strong following wind and sea, a heavily laden double-hulled vessel required competent handling in adjusting to combinations of wind and sea. Twyning observes that the sea has to be kept on the quarter, for if a high wave was allowed to run between the two hulls, it could part them. Scudding before a gale could also make any of these craft difficult to control, and there was the danger of being overtaken by waves and pooping a heavy sea, which could wash over the length of the vessel. It is likely that experienced seamen would in such weather pay out a long line with buoyant material, such as wooden spars attached to act as a sea anchor, and ride out the storm or drag it astern to slow down, but there is no evidence of this in the Pacific. Some vessels carried a heavy stone on a rope for anchoring.. This could be hung in the water over the bow, then weights shifted aft and the vessel kept nearly head-on to the sea, assisted by expert use of a steering oar. Morrison also observed in Tonga that "when taken by a squall they luff head on to it and shake it out—if long they jump overboard and hang her head to windward till the squall is over." He added that bringing the sail down on very big vessels could be dangerous, but they carried plenty of cordage and masts to repair damage.

Calm weather could bring other problems, particularly where strong ocean currents were encountered.... The equatorial current can set in a westerly direction at thirty to forty miles per day, and under fresh trade winds at about three and a half knots. The easterly countercurrent has a rate that reaches over one knot. These currents vary seasonally, with the equatorial countercurrent extending just south of the equator in June and July. Captain G. H. Heyen, who commanded the brigantine Alexa, the last sailing vessel to operate regularly out of Sydney to the Pacific Islands in 1929, recalls becoming becalmed twenty miles west of Tarawa on the fifty-fifth day out of Sydney and drifting away; the Alexa did not reach the Gilberts again for another one hundred days.