This discussion seems to be proceeding on the assumption that boats were designed with front overhang only for the purposes of aesthetics, or in an attempt to get around racing rules on monohulls by having an unmeasured increase in LWL when a boat heels. This assumption is false.
Naval architects have known for a couple of centuries that hull speed
in a non-planing hull
(the only hulls that existed 200 years ago) increased in proportion to the length of the waterline. The clipper ships and other sailing vessels of the past were designed with that in mind - i.e.. a particular waterline length was chosen, but then front overhang was added. Was this purely for reasons of aesthetics? Were those commissioning large clipper ships (or those commissioning smaller fishing
schooners such as the Bluenose) prepared to pay more more for an aesthetically pleasing overhang that added cost and worsened the performance of the vessel by adding weight and decereasing stability? Of course not. Were they designed with front overhang to take advantage of a rating rule
? No, as there were no rating rules.
IMO, one should think of a boat as being designed to a specific waterline with the subsequent consideration being whether the builder
(or customer) wishes to pay a little more for front overhang. There are several advantages:
1. Front overhang increases the area of the foredeck, assuming the coachouse and all other aspects of design remain the same. This facilitates sail and anchor
handling, etc., on a monohull
. It also permits a symetrical spinnaker
to be flown further forward off the bows of a catamaran
. This benefits self steering
2. Forward overhangs also reduce spray on the foredecks of both monohulls and multihulls. This is important if one has to go forward when underway.
3. Foreward overhangs provide additional bouyancy forward on the same waterline length - in extremis, the volume increases on three rather than two planes as the bow is depressed. This reduces the risk of burying a bow - a very dangerous phenomenon for both monohulls and multihulls that can lead to a pitchpole or capsize
. One of the earlier posts suggested that it would be harder for a submerged bow to resurface if there was a front overhang; no doubt true as the bow would be longer. However, the key is in avoiding burying a bow in the first place, where added front overhang has a distinct advantage.
4. On monohulls or trimarans (or catamarans such as mine, with bow rollers off each bow), front overhang reduces the tendancy of the anchor
banging into and damaging the topsides of the boat as it is being hoisted back aboard.
As naval architect Robert Perry wrote in Sailors' Secrets - Advice from the Masters,
Michael Badham and Robby Robinson, International Marine
, Camden, 1999 at p. 193:
"Some things, though, begin to look better the heavier the weather
gets. Plumb stems are a modern trend. The obviously can maximize waterline length, but in a cruising boat do you want to give up a foredeck and make your boat into a submarine....? Traditional elements like overhang are traditional because they work."
While the advantages are less compelling in a cat than a monohull
or a trimaran
, nevertheless there are still some valid reasons for specifying a bow with some overhang on any boat.