# C&C 27 MK I

1970 — 1972
Designers
Robert Ball
C&C Design
Builder
C&C Yachts
Association
C&C 27 Association
# Built
167
Hull
Monohull
Keel
Fin
Rudder
Construction
FG w/balsa cored deck

### Dimensions

Length Overall
27 3 / 8.3 m
Waterline Length
22 2 / 6.8 m
Beam
9 2 / 2.8 m
Draft
4 3 / 1.3 m
Displacement
5,180 lb / 2,350 kg
Ballast
2,510 lb / 1,139 kg (Lead)

### Rig and Sails

Type
Sloop
Reported Sail Area
344′² / 32 m²
Total Sail Area
344′² / 32 m²
Sail Area
150′² / 13.9 m²
P
28 6 / 8.7 m
E
10 5 / 3.2 m
Air Draft
?
Sail Area
195′² / 18.1 m²
I
33 0 / 10.1 m
J
11 9 / 3.6 m
Forestay Length
35 0 / 10.7 m

Make
Universal
Model
Atomic 4
HP
?
Fuel Type
Gas
Fuel Capacity
?

### Accomodations

Water Capacity
?
Holding Tank Capacity
?
?
Cabins
?

Hull Speed
7.4 kn
Classic: 6.31 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

7.35 knots
Classic formula: 6.31 knots
Sail Area/Displacement
18.4
16-20: good performance

### 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.
18.38
<16: under powered
16-20: good performance
>20: high performance
Ballast/Displacement
48.5
>40: stiffer, more 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

48.47
<40: less stiff, less powerful
>40: stiffer, more powerful
Displacement/Length
212.0
200-275: 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
212.01
<100: ultralight
100-200: light
200-300: moderate
300-400: heavy
>400: very heavy
Comfort Ratio
17.5
<20: lightweight racing 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
17.48
<20: lightweight racing boat
20-30: coastal cruiser
30-40: moderate bluewater cruising boat
40-50: heavy bluewater boat
>50: extremely heavy bluewater boat
Capsize Screening
2.1
>2.0: better suited for coastal cruising

### 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
2.12
<2: better suited for ocean passages
>2: better suited for coastal cruising

### Notes

The C&C 27 (MK I-IV) was one of C&C Yachts most successful model. Almost 1000 were built over a period of nearly 10 years.(Until 1982)

Mark I (hulls 1-167)(shown here)

Mark II (168-452), produced from 1972 to 1974.
Same dimensions as Mark I, except for a taller rig though with same sail area and other minor changes.

Mark III (hull #s 435-915) (1974-1981. (See C&C 27 MK III)
Taller rig than MKII. Hull stretched but beam is the same. Deeper keel with less ballast. Higher aspec rat. rudder. Same interior layout with minor changes.)
Wheel steering introduced as an option in 1976.
Diesel power offered as an option in 1978.
Later, the Yanmar SYP 12 diesel became standard.

Mark IV (916-972) ran from 1981 to 1982.
Same dimensions as Mark III, except the forestay was set back about four inches to accommodate a bow roller (resulting in a reduced ‘J’ measurement.)
Std. auxiliary power became Yanmar 2GM.

(The C&C 27 MK V is totally new design)

Another version (similar to C&C 27 MKI) called the TRAPPER 500 was built in the UK.
An ‘unauthorized’, most likely ‘splashed’, version was built in Germany called the KORNEUBURG 27 or K 27.
C&C 27 MK I available with a taller rig:
I: 35.00’/10.67m
J: 11.80’/3.60m
P: 29.80’/9.08m
E: 9.80’/2.99m
Total SA: (100%): 352.52 ft2/32.75 m2

### For Sale

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