Originally Posted by philip van praag
this is all about speed and comfort
but no one has said at what speed a boat becoms fast is 2knt or 30
what is comfort 5 permant crew to cater for your every need
how can you have all spent 8 pages decussing something that all of you peseve to be diferent.
set some perameters please:
speed range for a slow boat
speed range for a fast boat
speed range for average crusing boat
average length for a crusing mono/multi
name 5 onboard items that are for comfort only and can be removed for speed
Seeing as you seem to be being ignored I'll have a shot. My answers may be different to what you expect though because it is not about comparing knots between boats but expressing in terms that recognises that small boats can be fast but not as fast as bigger boats can be.
Needs maybe 15-20 knots wind speed at least to get to displacement speed. Or gets to displacement speed at lesser wind strengths but cannot maintain that in face of regular seas/winds up to gale or cannot maintain that without unreasonable loss of crew comfort (no boat under 120 foot is comfortable EVER
). Wallows and rolls downwind. Has a lowish displacement speed for WL (ie because of high wave making resistance due to high displacement and/or less efficient hydrodynamics - I will not mention Froude number
Visual clues - Often long keeled or keel and skeg integrated with keel, ballast carried high, no spade rudder
(not unusual to see very inefficient barn door rudders hung off the vertical), deep canoe draft
(draft waterline to bottom of keelson) and full sections, may be ketch/yawl rigged (am not inferring all such are slow boats) and if not will likely have a low aspect ratio rig, cutter
Reaches displacement speed at around 7-8 knots of wind speed and can maintain that in face of seas/winds up to gale for boat length while maintaining crew comfort. Will sail fast and true downwind in most conditions expected of a boat of same WL length eg for 50+footer to do so in Force 9 and even Force 10 if seas have not fully built. Has high displacement speed for hull
length due to low displacement and efficient hydrodynamics. It may or may not have enough power to get over the hump and plane, that depending on sail area but will readily surf if so driven.
Some visual cues - Fast Boat typically have simple fore and aft rigs without overlapping foresails, may just have a single
part mainsheet taken via a block to a winch
with powerful vang and no traveller. Maybe two close spaced furled foresails to give efficient foresail area management. May carry a spinnaker
but more likely rely on gennaker(s) on line furlers for ease of sail handling, often with a prod for them. SA/D will be high but sail area for boat length may be comparatively low (SA/D ratio being high because of low D). Shallow canoe draft
, be fin keeled with ballast carried low, static WL length will be close to same as length over deck
, spade rudder
. Look at Bob's Icon on his web page.
AVERAGE SPEED YACHT
Somewhere in between the above.
5 THINGS FOR COMFORT ONLY THAT COULD BE REMOVED
Boats over around 45 foot - nothing need be gone without. As an example a very fast and comfortable 50+ footer I am familiar with has interior
fitted out to meticulous standard in so far as joinery (but extensive use of foam sandwich overlaid with veneer for structural bulkheads, partitioning, cabinetry, etc), finishes and soft furnishings is concerned (and I say that from the perspective of being familiar with the finishes in super yachts). It carries a generator
fuelled heater of capacity suitable for high latitude cruising, freezer
, microwave, breadmaker, etc, etc all as one would hope for in a high quality liveaboard
systems appropriate to unlimited independent cruising. This boat is the owner's home and has been proven to be able to make very fast comfortable passages for its WL including sailing frequently in high latitude heavy weather
Smaller boats, what you put in them may count more as against total displacement but there again you can't fit so much in them because of lack of room so I would expect a fitout as cosy as any boat of similar volume. If you want a complete engineering workshop on board and are an inveterate junk collector/beach comber, consider that you need six anchors and several thousand feet of cable amongst them all to suit any occasion, etc, etc I suspect one would not be of the temperament to be even looking at boats such as these.