This thing about righting a cat illustrates that, from these postings, not enough people sailing on cats are fully aware of the proper techniques to right one that has ditched! As I described in my earlier post, ANY off the beach cat, (at least up to the size of a Tornado) can be righted quite quickly and safely by ONLY ONE PERSON, if the method that I described is followed! You do not "pull" a Cat up, you use the wind that has knocked you over to "sail" the cat into the upright position. It is efficient and leaves the crew in a much more physically competent way (they are not exhausted) than they were when they went into the water.
On the subject of "fully vented masts", at the head and at the base, sure when the head of the mast hits the water it will start to fill BUT, the surface of the water in the mast will always only remain at the level of the surface of the surrounding water, and water in water weighs nothing in relation to the crew trying to right it, the weight of water in the mast only effects the crew when it is contained and lifted free of the surounding water, and this means that the only weight that has to be supported by the crew is the actual weight of the mast. With the crew supporting the cat in the 90 degree position by "leaning" out on a righting rope they can easily support that weight, and the mast being in the position that the head is lower than the base (the base being above the water level as it is positioned in the centre of the cat which is half the beam of the cat above the water) allows, any water in the mast to flow out the head,IF THE BASE IS ALSO VENTED, so that there is no "suction" trying to impede that water flow. By having both head and base vented, the mast, in any attitude above water, will never hold water, and that can often be the main problem with "SEALED" masts. It is very rare that a so called "sealed" mast ever remains sealed for any length of time. The biggest problem is that every fitting and hole that is attached to or drilled into a mast, has to be sealed and by the nature of attaching two different types of material together, then trying to seal them with a third "compound" is fraught with the possibility (usually fact) that due to the different linear coefficient of expansion of different materials, that seal will not remain intact. once the integrety of the seal on any of the entrys to the mast are compromised, then, when the mast is submerged water will be forced into the mast under pressure, BUT when that pressure is removed (the mast comes out of the water) that water will either not drain from the mast or else it will drain very very slowly making the mast many times it's own weight.