Hard to come up with a modern example, as everything is so similar today: boats are designed to fully fill out a standard slip.
So, rolling back the calendar to a day when there were two closely matched boats, one wide, one narrow: Windward Passage
(wide) and Blackfin (narrow). Displacements were very similar (90K lbs for Passage
, 110K lbs for Blackfin). Sail area very similar, both ketches, same waterline, same rating (maximum).
Upwind in smooth water
and moderate to heavy air, Passage was faster. I think this was due to 'Passage having more stability, but it could have been also due to Blackfin's poorly designed keel
foil section (sharp leading edge to the keel
, and flat plate centerboard). In all other conditions, Blackfin seemed to be the faster boat.
Upwind in heavy seas, the wide hull
handled very oddly: as the boat went over big (10 to 20 foot) seas, 'Passsage would have a very balanced helm
when going up the face of the wave, and then tremendous weather helm
going across the crest and back down into the trough. I had to turn the wheel
about 180 degrees with every wave.
Downwind, both boats handled well and were very close to the same speed (Blackfin a little faster), but Blackfin handled a little better: Passage had to be steered (barely), while on Blackfin the contest was how many waves you could let the boat surf between touching the helm!
Also, the motion of the two boats was markedly different, with Passage pitching with much higher accelerations (more abrupt) than Blackfin.
The huge and convincing difference however was in the amount of work required to sail the two boats. The wide (therefore stiff and high wetted surface) 'Passage required a lot of sail under a lot of load. Blackfin could be sailed very fast with very small sails
. In fact, the hardest lesson on Blackfin was just how quickly we needed to shorten sail to go fast: the required sail area was so little it was quite easy to sail Blackfin with as few as 4 people. I am quite sure 'Passage was never sailed with less than a dozen burley crew. This was in the times of no autopilot
, no powered winches, and very heavy Dacron sails
(modern sail cloth is MUCH lighter).
Based on these, admittedly dated, experiences, I feel that narrow is better in the following ways:
1) Better speed in nearly all conditions
2) Better handling, more fun to steer and sail
3) Better motion in seaway
4) Far less motive power required
But obviously, narrow is worse in the following ways:
1) More expensive dock fees
for a given internal volume (fat fills the slip)
2) Less volume for a given length
3) More difficult interior