Boat Design Alternatives- For Blue Water Boats
Stern configuration- Double end versus normal
Double end
Presents less stern area to high following seas
Generally used in conjunction with aft cockpit (see below)
Normal stern
Stern has more flotation so it rises above following seas
More internal space for storage including possible lazerette
Better able to mount dinghy davits
Can have sugar scoop stern (see below)
Conclusion: Normal stern wins hands down
Stern configuration- Conventional versus “sugar scoop”
Conventional (forward or aft slant)
Difficult boarding except with side ladder, especially from the water
“Sugar Scoop” stern
Provides easy location for boarding from the water or dinghy (The front door “porch”)
Major safety benefit for recovery of man overboard (either solo or with assistance)
Provides bathing and shower platform
Unaffected by seas
Conventional with deploying platform or ladder
Provides sugar scoop features if deployed
Not useful for accidental man overboard
Depending upon design, could be battered by heavy seas
Conclusion: Sugar scoop clearly better functionally for a cruiser
Keel configuration
Full length
Excellent forward tracking
Prevents lines entangling in enclosed propeller
Large area to minimize side drift
Partial length
Less wetted area yields less drag and faster speeds
Better backing control
Easier turning at lower speeds (marina maneuvering)
Permits use of solid lead bulb to make boat stiffer with less draft
Solid lead at bottom provides good protection during grounding
Medium length gives good forward tracking with minimum side drift
Conclusion: Medium length best compromise; better with solid lead bulb for possible
grounding (Encapsulated iron bits not recommended)
Hull material
Fiberglass (GRP)
Easy to maintain
Possible osmosis if not built properly
Steel
Very strong against puncture
Rust issues require constant maintenance
Electrolysis issues
Framing and insulation takes space inside boat
Condensation issues
Noise issues
Aluminum
Strong against puncture
Electrolysis issues
Framing and insulation takes space inside boat
Condensation issues
Noise issues
Conclusion: Fiberglass better under normal circumstances. Steel or aluminum better for
collisions. Choice dependent upon risk analysis.
GRP Hull construction
Solid lay-up in the hull
Heavier for equal strength compared to cored construction
Better for penetration resistance
Cored construction
Lighter for equal strength compared to solid
If outer skin is penetrated there is a major loss of strength & core will absorb water
Conclusion: Difficult decision. If concerned about possible penetration then solid is better.
Cockpit location
Aft cockpit
Location will yield more pitch and less roll motion for occupants than center cockpit
Able to see whole mainsail from cockpit
Farther from bow will yield less spray; more significant for shorter boats
Generally precludes large full height aft cabin
Close to following seas
Generally precludes poop deck and lazarette
Difficult to place dinghy davits that are out of the way
Center cockpit
Location will yield less pitch and slightly more roll for occupants than aft cockpit
For larger boats (above 45’) spray is not an issue, & cockpit is higher above water
Permits large aft cabin and good salon layout; i.e. galley aft and not in main salon
Easy to see widest part of boat when docking
Permits poop deck, lazarette, and dinghy davits
Permits better location of main sheet and traveler aft of the cockpit
Often permits better bimini design
Conclusion: For boats over 45’ center cockpit is better
Saloon configuration
Conventional salon
Deep and dark
Longer companionway stairs
Raised deck salon
Bright and airy feeling
Easier to see out
Able to place heavy items such as batteries, fuel & water under sole, farther below
Conclusion: Raised deck salon is superior
Rig
Ketch
More sail configurations available for balanced sailing
Less mast height
Can use aft sail to minimize swinging at anchor
More lines to handle
Harder to tack
Harder to configure deck and cockpit
Sloop
Easier to handle short handed
More sail area higher so better for light winds
Sloop with cutter staysail (Cutter rig)
Harder to go about as genoa or yankee can ”hang up” in slot between the two forestays
Better for heavy weather as staysail can be used as a storm sail with “balance”
Conclusion: Sloop better overall, cutter better yet
Foresail configuration
Jenny
Basically a foresail that overlaps the mast, and the foot is at deck level
Large sail area
Yankee
Basically a foresail that overlaps the mast, and the foot rises to a clew above deck
Smaller sail area, but area of loss is close to water, maybe not critical
Easy to see under sail
Sail does not conflict with lifelines
Easier to use spinnaker pole to pole out yankee for downwind sailing
Conclusion: Yankee better for cruising
Dinghy storage
Dinghy davits
Convenient, easy storage
Dinghy can be deployed in two minutes
Dinghy extending past stern can be a problem when backing down between boats and
when departing docks with high obstructions
Dinghy can be stowed or deployed easily by one person
Can be used with hard or inflatable dinghies (inflatable more typical)
Secure even in extremely rough seas
On deck
Difficult and time consuming to stow; generally requires two people
Requires lifting dinghy on deck either for deflating inflatable or dinghy tie down
Takes up deck space and sometimes interferes with sails
Reduces visibility
Garage or forward deck compartments
Only available for very large boats
Conclusion: Dinghy davits are best solution for medium length boats
Stern boarding
Passerelle
Required for typical stern-to docking in Europe and rest of world
If arranged properly, dinghy can be left on davits hanging under Passerelle
No Passerelle
Difficult or impossible situation for most of the world
Conclusion: Passerelle required for world cruising
Shore voltage compatibility
240 Volt AC connection
Suitable for Europe and rest of world
Suitable for most of US and especially in areas where A/C use on boats is typical
Arrange for components to work with both 50 or 60 hertz for maximum flexibility
Requires 240 Volt appliances (vacuum, toaster, etc.)
Can use “reverse Y” when only 120 VAC is available
120 Volt AC Connection
Only suitable for use in the US
Conclusion: Equip boat for 240 VAC shore connection
Rudder configuration
Spade
Minimizes wetted area
More control for size
Skeg or partial skeg
Prevents rudder from falling out
Reduces side loads on main rudder bearings
Full skeg provides point of contact when grounding
Conclusion: For cruising, full or partial skeg mounting is preferred
Autopilot
Windvane
Uses no power
Downwind sailing (typical in the trade winds) is not the best point of sailing for control
due to reduced wind velocity on vane
Takes space on stern, possibly precludes sugar scoop
May preclude Passerelle
Requires removal of in-water rudder when backing up
Not useful for motoring without wind
Better on smaller boats, under 45’
Electric or hydraulic
Uses power continuously
Good, dependable operation under sail and power at all points of sail
If properly sized can handle boat even in Force 10 storm conditions
Best approach is rams acting directly on rudder stock. This provides a back-up the
normal cable steering as steering can be accomplished without the cables
Can be used to follow desired track, or heading or wind angle
Most reported problems can be traced to undersize units or units using belt drive to
steering wheel
Conclusion: Electric/ hydraulic far superior to windvane, even considering power consumption
Other desirable features for good cruising
Large Lazarette
Two anchors mounted on bow rollers (one with at least 50 meters of chain rode)
Sails rigged for short handed sailing so boat can be sailed from cockpit
Self-tailing winches, powered primaries in larger boats
Power furling of main and yankee
Boat divided into watertight compartments
Seakindly in addition to seaworthy
Faster rather than slower
Positive stability range to at least 125 degrees
Bow thruster
Bimini for sun and rain protection that can be left up while sailing
Large, good refrigerator and freezer
Plenty of storage space
Generator, and air conditioning
Large battery set
Fuel tank large enough to provide for a motoring range of 1,000 NM
Water maker
Folding or feathering propeller; rope cutter on prop shaft
Heating or cooling systems depending on where the boat will be sailing
