Islander 44 is a 43′ 9″ / 13.4 m monohull sailboat designed by C. William Lapworth and built by Islander / Tradewind Yachts starting in 1962.
- Designer
- C. William Lapworth
- Builder
- Islander / Tradewind Yachts
- Associations
- ?
- # Built
- 10
- Hull
- Monohull
- Keel
- Fin
- Rudder
- Spade
- Construction
- FG
Dimensions
- Length Overall
- 43′ 9″ / 13.4 m
- Waterline Length
- 32′ 6″ / 9.9 m
- Beam
- 10′ 11″ / 3.4 m
- Draft
- 5′ 10″ / 1.8 m
- Displacement
- 22,500 lb / 10,206 kg
- Ballast
- 8,000 lb / 3,629 kg
Rig and Sails
- Type
- Sloop
- Reported Sail Area
- 813′² / 75.5 m²
- Total Sail Area
- 838′² / 77.9 m²
Mainsail
- Sail Area
- 417′² / 38.7 m²
- P
- 43′ 4″ / 13.2 m
- E
- 19′ 2″ / 5.9 m
- Air Draft
- 54′ 0″ / 16.5 m
Foresail
- Sail Area
- 421′² / 39.2 m²
- I
- 49′ 0″ / 14.9 m
- J
- 17′ 2″ / 5.2 m
- Forestay Length
- 51′ 11″ / 15.8 m
Auxilary Power
- Make
- Universal
- Model
- Unimite
- HP
- 72
- Fuel Type
- Diesel
- Fuel Capacity
- 60 gal / 227 l
Accomodations
- Water Capacity
- 60 gal / 227 l
- Holding Tank Capacity
- ?
- Headroom
- ?
- Cabins
- ?
Calculations
- Hull Speed
-
8.1 kn
Classic: 7.64 kn
Hull Speed
The theoretical maximum speed that a displacement hull can move efficiently through the water is determined by it's waterline length and displacement. It may be unable to reach this speed if the boat is underpowered or heavily loaded, though it may exceed this speed given enough power. Read more.
Formula
Classic hull speed formula:
Hull Speed = 1.34 x √LWL
A more accurate formula devised by Dave Gerr in The Propeller Handbook replaces the Speed/Length ratio constant of 1.34 with a calculation based on the Displacement/Length ratio.
Max Speed/Length ratio = 8.26 ÷ Displacement/Length ratio.311
Hull Speed = Max Speed/Length ratio x √LWL
- Sail Area/Displacement
-
16.3
Sail Area / Displacement Ratio
A measure of the power of the sails relative to the weight of the boat. The higher the number, the higher the performance, but the harder the boat will be to handle. This ratio is a "non-dimensional" value that facilitates comparisons between boats of different types and sizes. Read more.
Formula
SA/D = SA ÷ (D ÷ 64)2/3
- SA: Sail area in square feet, derived by adding the mainsail area to 100% of the foretriangle area (the lateral area above the deck between the mast and the forestay).
- D: Displacement in pounds.
- Ballast/Displacement
-
35.6
<40: less stiff, less powerful
Ballast / Displacement Ratio
A measure of the stability of a boat's hull that suggests how well a monohull will stand up to its sails. The ballast displacement ratio indicates how much of the weight of a boat is placed for maximum stability against capsizing and is an indicator of stiffness and resistance to capsize.
Formula
Ballast / Displacement * 100
- Displacement/Length
-
292.3
200-300: moderate
Displacement / Length Ratio
A measure of the weight of the boat relative to it's length at the waterline. The higher a boat’s D/L ratio, the more easily it will carry a load and the more comfortable its motion will be. The lower a boat's ratio is, the less power it takes to drive the boat to its nominal hull speed or beyond. Read more.
Formula
D/L = (D ÷ 2240) ÷ (0.01 x LWL)³
- D: Displacement of the boat in pounds.
- LWL: Waterline length in feet
- Comfort Ratio
-
39.5
30-40: moderate bluewater cruising boat
Comfort Ratio
This ratio assess how quickly and abruptly a boat’s hull reacts to waves in a significant seaway, these being the elements of a boat’s motion most likely to cause seasickness. Read more.
Formula
Comfort ratio = D ÷ (.65 x (.7 LWL + .3 LOA) x Beam1.33)
- D: Displacement of the boat in pounds
- LWL: Waterline length in feet
- LOA: Length overall in feet
- Beam: Width of boat at the widest point in feet
- Capsize Screening
-
1.6
<2.0: better suited for ocean passages
Capsize Screening Formula
This formula attempts to indicate whether a given boat might be too wide and light to readily right itself after being overturned in extreme conditions. Read more.
Formula
CSV = Beam ÷ ³√(D / 64)
- Beam: Width of boat at the widest point in feet
- D: Displacement of the boat in pounds
Notes
Hull mold for LAPWORTH 44 purchased by Islander (1965-original builder unknown) and name changed to ISLANDER 44. (The designer, Bill Lapworth, has said that his involvement with this boat ended here.) After purchasing, Islander reconfigured hull to a long keel. Some tooling later went to Yachtcraft which sold them principly as kits. These were known as the YACHTCRAFT 44, OR 41 (with a chopped stern - also sometimes called ISLANDER 41*).
Deck, coach roof profile and other details vary between versions. (deck mold may have been adapted from an another Islander model)
(*There are actually 2 different boats from Islander/Wayfarer called the ISLANDER 41. The other is designed by Gurney and both are rare.)
(See ISLANDER 41.)
