[sailaway21]

Regarding ships, which do not ride the same as sailboats, Jeff's logic would be completely backwards. The plumb bow is not seen on ocean going vessels for just the original reason Plumper pointed out, the tendency to bury the bow, loading tons of water on the foredeck. Rather than pounding, the flare of the bow, as the bow descends, provides increased buoyancy resulting in not only the bow rising but a tendency to part a sea versus knife through. The deeper the bow plunges, the more she'll tend to rise and as she does slamming becomes a factor. No vessel can take prolonged slamming of the bow for long. The tremendous clipper flare to a ship's bow resists this quite well. You'll notice on a destroyer, an extreme example, that the fineness of entry is carried nearly 25% of the vessel's length aft at the level of the keel. Given their extreme motions in a seaway this is essential to prevent slamming which might be considered as the slapping of bottom plating on the sea as the bow descends.

Very few sailboats have a true plumb bow as seen on ships. Most do not have the clipper type bow seen on most modern ships, either. Ships tend to have a much finer and longer entry than on sailboats. The spoon bows seen on many sailboats are effective in wavelengths of greater length than the vessel and that does not often occur on ships.

If you examine ships of the early twentieth century you'll see that their plumb bow had very little flare and this was their death knell design wise. When you start burying the bow of a ship you're going to encounter structural damage sooner than later.

I too am somewhat sceptical of the current plumb bow on sailboats if only for the wet ride. That they do not bury their bows
more than they do I'd ascribe to the fact that they do not carry their fineness of entry very far aft and that they're relatively small in proportion to wavelength. Like many, the aesthetics leave me ambivalent. (g)