Join Date: Feb 2000
Location: Annapolis, Md
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What makes a functional cruiser?
While I am a fan of many of Bob Perry''s cruising designs, jsgsail''s post seems to imply some fairly major misconceptions.
To begin with when you talk about a cruising boat, displacement is a better measurement of size and carrying capacity than length. Historically there was a tendancy to think that there is an advantage to cramming more displacement into a shorter sailing length. Nothing is further from the truth.
All things being roughly equal, a longer boat of the same displacement will have greater carrying capacity, equal or less initial cost and equal or lower maintenance costs, greater seaworthiness, speed, ease of handling, more room for accomodations and will have a more comfortable motion.
In sizing a boat there is an optimal displacement per person (traditionally 2 1/2 to 5 long tons) and all things being roughly equal, a boat with the displacent that you are seeking and with a lower L/D will generally be a better boat all around.
Substanially heavier hull thickness is generally a mark of a poorly engineered boat. Adding fiberglass laminate to a hull is a relatively inexpensive but terribly inefficient way to increase the strength of a boat. It is far less effective than designing and building a proper laminate and framing system. This extra thickness is often achieved with the use of a higher percentage of non-directional laminates (mat or chopped glass). Non-directional laminates are seen as greatly reducing impact resistance and greatly increasing the tendancy towards fatigue. A thicker hull made up with a larger percentage of non-directional material may have a much smaller resistance to puncture and be a lot more flexible and fatigue prone than a lighter hull that has a properly engineered framing system and laminate.
Comparing rigging between boats in and of itself tells you nothing about the actual strength of the rig. Beamier, heavier weight boats for their length, such as the Island Packet, place much higher stresses on their
rigs and so heavier rigging is required to equal the strength of a lighter boat with lighter rigging. Similarly boats like the Swan with its narrow spreader and shroud width, produce much higher rigging loads than a less performance oriented rig.
Lastly, in and of iteself weight does nothing good for a boat. Weight does not make a boat stronger, greater weight does not allow a boat to have a greater carrying capacity, greater weight does not give a boat a more comfortable motion, greater weight does not make it more seaworthy, greater weight does not automatically produce a boat that has more stability, greater weight does not make the boat easier to handle, greater weight does not make a boat that has better accomodations, in fact, in and of itself, greater weight does not make a boat better in any way. Weight only breeds more weight and that means greater maintenance costs, bigger ground tackle, higher stresses, lower fuel efficiency, and more work for the crew.