Back to Search

Cape Dory 300 Ms

Designer: Clive M. Dent  ·  Builder: Cape Dory Yachts (Usa)  ·  First built: 1985
+ Add to Compare
Videos
About the Cape Dory 300 Ms

Built during Cape Dory's golden era from 1985 to 1990, this masthead sloop represents the yard's commitment to traditional cruising values with modern construction techniques. Designer Clive M. Dent created a robust coastal cruiser that emphasizes seaworthiness over speed, evident in the boat's substantial 11,500-pound displacement and conservative sail plan of 442 square feet. The 300 Ms features Cape Dory's characteristic long keel configuration, providing excellent directional stability and a forgiving helm in challenging conditions. With a moderate draft of 3.92 feet, she can access many harbors while maintaining the tracking ability that long-keel designs are prized for. The generous beam of 11.42 feet creates a stable platform and spacious accommodations below. Her impressive comfort ratio of 25.22 and conservative capsize screening value of 2.03 indicate exceptional seaworthiness, making this an ideal choice for serious coastal cruising and short offshore passages. The 46-horsepower engine provides reliable auxiliary power when needed. With only 47 hulls produced, the 300 Ms represents an exclusive entry in Cape Dory's respected lineup, appealing to sailors who prioritize safety, comfort, and traditional sailing characteristics over racing performance.

Core Dimensions
LOA (Length Overall) 29.85 ft / 9.10 m
LWL (Waterline Length) 26.50 ft / 8.08 m
Beam 11.42 ft / 3.48 m
Max Draft 3.92 ft / 1.19 m
Displacement 11,500.00 lb / 5,216 kg
Ballast 4,500.00 lb / 2,041 kg
Ballast Type Lead
Sail Area (Reported) 442.00 ft² / 41.06 m²
Design & Construction
Hull Type Long Keel
Rigging Type Masthead Sloop
Construction FG
Designer Clive M. Dent
Builder Cape Dory Yachts (USA)
First Built 1985
Last Built 1990
Number Built 47
Associations Cape Dory Sailboat Owners Association
Related Sailboats Pearson 30 · Catalina 30 Mkii · Morgan Out Island 30 · Seidelmann 30 · S2 92 C
Owner Reviews

No owner reviews yet — be the first to share your experience with this boat.

Known Issues & What to Watch For

No known issues documented for this model yet.

Own or have surveyed a Cape Dory 300 Ms? Submit a known issue

Performance Ratios
PHRF Rating PHRF (Performance Handicap Racing Fleet) is a national racing handicap measured in seconds per nautical mile. Lower values indicate faster boats. Ratings are sourced from US Sailing's national database (median across 60+ regional fleets).
Under 0 — Ultralight racer0–90 — Performance racer90–150 — Cruiser/racer150–210 — Typical cruiserOver 210 — Heavy/slow cruiser
 293
SA/Displacement Sail Area to Displacement ratio measures how much sail power a boat has relative to its weight. Higher values mean more performance and speed.
Under 14 — Heavy cruiser, slow14–18 — Cruising sailboat18–22 — Cruiser/racerOver 22 — Performance racer
 13.93
Ballast/Displacement Ballast to Displacement ratio shows what percentage of the boat's total weight is ballast. Higher values generally mean better initial stability and stiffer sail carrying.
30–35% — Typical cruiser35–45% — Stiff performance boatOver 45% — Racing oriented
 39.13
Displacement/Length Displacement to Length ratio measures how heavy a boat is relative to its waterline length. Lower values mean a lighter, faster boat.
Under 100 — Ultralight racer100–200 — Light cruiser/racer200–300 — Moderate cruiser300–400 — Heavy cruiserOver 400 — Very heavy
 275.87
Comfort Ratio Ted Brewer's Comfort Ratio predicts how comfortable a boat will feel in offshore conditions. Higher values mean a steadier, more comfortable motion in a seaway.
Under 20 — Uncomfortably rough20–30 — Acceptable coastal30–40 — Good offshore comfortOver 40 — Very comfortable offshore
 25.22
Capsize Screening Formula The USHS Capsize Screening Formula estimates offshore capsize risk. Lower is safer — values under 2.0 are considered acceptable for offshore sailing.
Under 2.0 — Safe for offshore2.0–2.2 — Borderline offshoreOver 2.2 — Coastal use recommended
 2.03
Hull Speed Hull Speed is the theoretical maximum speed of a displacement hull, calculated from waterline length. Most cruising sailboats reach this speed in moderate conditions. 6.90 kn
S# (Speed Number) The Speed Number (S#) is a quick performance index. Higher values indicate a faster, more powerful design relative to its size.
Under 3.0 — Slow cruiser3.0–5.0 — Average cruiser5.0–7.0 — Performance cruiserOver 7.0 — Racer
 1.77
Pounds/Inch Immersion Pounds per Inch Immersion (PPI) tells you how much weight is needed to sink the boat one inch. Useful for calculating how additional gear and stores affect waterline. 1,081.33 pounds/inch
SA/Displacement (Calc) Calculated Sail Area to Displacement ratio using actual measured sail dimensions rather than reported values. More precise than the reported SA/Disp figure. 15.04
Rig Dimensions
I (Foretriangle Height) 40.75 ft / 12.42 m
J (Foretriangle Base) 12.83 ft / 3.91 m
P (Mainsail Luff) 35.25 ft / 10.74 m
E (Mainsail Foot) 12.25 ft / 3.73 m
SA Fore 261.41 ft² / 24.29 m²
SA Main 215.91 ft² / 20.06 m²
SA Total (100%) 477.32 ft² / 44.34 m²
Est. Forestay Length 42.72 ft / 13.02 m
Mast Height (DWL) 46.50 ft / 14.17 m
Engine & Accommodations
Engine Make Westerbeke
Engine Model W-46
Engine Type Diesel
Horsepower 46
Fuel Capacity 50 gals / 189 L
Water Capacity 75 gals / 284 L
How It Compares

vs. Catalina 30 Mkii, Morgan Out Island 30, Pearson 30, S2 92 C, Seidelmann 30

This boat Similar boats
Dimensions
LOA
Cape Dory 300 Ms ★
29.9 ft
Catalina 30 Mkii
29.9 ft
Morgan Out Island 30
29.8 ft
Pearson 30
29.8 ft
S2 92 C
29.9 ft
Seidelmann 30
29.8 ft
LWL
Cape Dory 300 Ms ★
26.5 ft
Catalina 30 Mkii
25.0 ft
Morgan Out Island 30
24.8 ft
Pearson 30
25.0 ft
S2 92 C
25.0 ft
Seidelmann 30
25.0 ft
Beam
Cape Dory 300 Ms ★
11.4 ft
Catalina 30 Mkii
10.8 ft
Morgan Out Island 30
9.2 ft
Pearson 30
9.5 ft
S2 92 C
10.3 ft
Seidelmann 30
12.0 ft
Displacement
Cape Dory 300 Ms ★
11 lbs
Catalina 30 Mkii
10 lbs
Morgan Out Island 30
9 lbs
Pearson 30
8 lbs
S2 92 C
9 lbs
Seidelmann 30
9 lbs
Ballast
Cape Dory 300 Ms ★
4 lbs
Catalina 30 Mkii
4 lbs
Morgan Out Island 30
3 lbs
Pearson 30
3 lbs
S2 92 C
4 lbs
Seidelmann 30
4 lbs
Sail Area
Cape Dory 300 Ms ★
442 sq ft
Catalina 30 Mkii
437 sq ft
Morgan Out Island 30
375 sq ft
Pearson 30
445 sq ft
S2 92 C
468 sq ft
Seidelmann 30
—
Performance
PHRF Rating (lower = faster)
Cape Dory 300 Ms ★
293 s/nm
Catalina 30 Mkii
186 s/nm
Morgan Out Island 30
—
Pearson 30
174 s/nm
S2 92 C
—
Seidelmann 30
162 s/nm
SA / Displacement (higher = more powerful)
Cape Dory 300 Ms ★
13.9
Catalina 30 Mkii
14.9
Morgan Out Island 30
13.4
Pearson 30
17.4
S2 92 C
16.4
Seidelmann 30
—
Ballast / Disp (higher = stiffer)
Cape Dory 300 Ms ★
39.1 %
Catalina 30 Mkii
41.2 %
Morgan Out Island 30
31.6 %
Pearson 30
42.8 %
S2 92 C
—
Seidelmann 30
47.9 %
Comfort Ratio (higher = more comfortable offshore)
Cape Dory 300 Ms ★
25.2
Catalina 30 Mkii
24.9
Morgan Out Island 30
29.2
Pearson 30
24.3
S2 92 C
25.8
Seidelmann 30
—
Capsize Screening (lower = safer)
Cape Dory 300 Ms ★
2.03
Catalina 30 Mkii
2.00
Morgan Out Island 30
1.73
Pearson 30
1.88
S2 92 C
1.92
Seidelmann 30
—
Displacement / Length (lower = lighter)
Cape Dory 300 Ms ★
275
Catalina 30 Mkii
291
Morgan Out Island 30
277
Pearson 30
237
S2 92 C
—
Seidelmann 30
268
Hull Speed
Cape Dory 300 Ms ★
6.9 kts
Catalina 30 Mkii
6.7 kts
Morgan Out Island 30
6.7 kts
Pearson 30
6.7 kts
S2 92 C
6.7 kts
Seidelmann 30
—
Speed Number (higher = faster)
Cape Dory 300 Ms ★
1.8
Catalina 30 Mkii
1.6
Morgan Out Island 30
1.6
Pearson 30
2.3
S2 92 C
1.9
Seidelmann 30
—
Find a Cape Dory 300 Ms For Sale
Y YachtWorld Brokerage listings S Sailboat Listings Sailboats only C Craigslist National search F Facebook Marketplace Local listings B boats.com Global marketplace