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Spencer 31
Designer: John Brandlmayr  ·  Builder: Spencer Boats  ·  First built: 1966
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About the Spencer 31

Designed by Canadian naval architect C.C. Brewer and built by Spencer Boats of Vancouver, British Columbia, the Spencer 31 earned a strong following along the Pacific Coast during the 1970s as a capable and versatile cruising sailboat. Known for their solid fiberglass construction and seaworthy hull designs, Spencer boats developed a reputation for building affordable yet dependable vessels that could handle coastal and offshore conditions with confidence. The Spencer 31 reflects this legacy, offering a well-balanced hull suited to bluewater passages and extended coastal cruising alike. Sailors who have owned and sailed these boats often praise their predictable handling, sturdy build quality, and comfortable motion in a variety of sea states. The design prioritizes stability and practicality, making it an appealing choice for liveaboards and passage-makers on a budget. With an active owners community and a track record of completing offshore passages, the Spencer 31 remains a respected choice among sailors seeking an honest, no-frills cruising boat. For those willing to look beyond newer production designs, it represents solid value and genuine bluewater capability.

Market Price Estimate Beta
Small sample size. This estimate is based on fewer than 5 listings and may not be representative of the true market. Use with caution.
$17,000 – $17,000
typical asking price
Median $17,000  ·  2 listings used
All listings
$17,000 – $17,000 2
Rate a listing price
$
About this estimate
  • Prices are based on recent asking prices from public listings — not actual sale prices, which are typically lower.
  • Condition is not factored in. A well-maintained boat with new sails and engine can be worth significantly more than a project boat of the same model.
  • Location affects price. Boats in landlocked states or areas with fewer buyers often sell for less than those on the coast.
  • Year of manufacture is not filtered. Older examples of this model will generally be priced lower than newer ones.
  • Included equipment varies widely. A boat with a full suite of electronics, dodger, and new standing rigging may command a large premium.
  • Outliers are automatically excluded using statistical filtering to improve accuracy, but some bad data may remain.
Core Dimensions
LOA (Length Overall) 31.00 ft / 9.45 m
LWL (Waterline Length) 24.00 ft / 7.32 m
Beam 9.17 ft / 2.80 m
Max Draft 5.00 ft / 1.52 m
Displacement 9,350.00 lb / 4,241 kg
Ballast 3,450.00 lb / 1,565 kg
Sail Area (Reported) 440.00 ft² / 40.88 m²
Headroom 6.17 ft / 1.88 m
Design & Construction
Hull Type Fin w/spade rudder
Rigging Type Masthead Sloop
Construction FG
Designer John Brandlmayr
Builder Spencer Boats
First Built 1966
Owner Reviews

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Known Issues & What to Watch For

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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
192
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
15.92
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
28.93
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
1.74
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. 6.56
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
1.65
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. 786.37
Rig Dimensions
I (Foretriangle Height) 37.0
J (Foretriangle Base) 12.5
P (Mainsail Luff) 31.0
E (Mainsail Foot) 13.5
SA Fore 231.25
SA Main 209.25
How It Compares

vs. Hughes 31, Longbow 31 Westerly, Rival 31

This boat Similar boats
Dimensions
LOA
Spencer 31 ★
31.0 ft
Hughes 31
31.0 ft
Longbow 31 Westerly
31.0 ft
Rival 31
31.0 ft
LWL
Spencer 31 ★
24.0 ft
Hughes 31
24.0 ft
Longbow 31 Westerly
25.0 ft
Rival 31
24.5 ft
Beam
Spencer 31 ★
9.2 ft
Hughes 31
9.7 ft
Longbow 31 Westerly
9.5 ft
Rival 31
9.7 ft
Displacement
Spencer 31 ★
9 lbs
Hughes 31
9 lbs
Longbow 31 Westerly
9 lbs
Rival 31
11 lbs
Ballast
Spencer 31 ★
3 lbs
Hughes 31
3 lbs
Longbow 31 Westerly
4 lbs
Rival 31
4 lbs
Sail Area
Spencer 31 ★
440 sq ft
Hughes 31
Longbow 31 Westerly
371 sq ft
Rival 31
Performance
PHRF Rating (lower = faster)
Spencer 31 ★
192 s/nm
Hughes 31
191 s/nm
Longbow 31 Westerly
Rival 31
SA / Displacement (higher = more powerful)
Spencer 31 ★
15.9
Hughes 31
Longbow 31 Westerly
13.4
Rival 31
Ballast / Disp (higher = stiffer)
Spencer 31 ★
Hughes 31
36.8 %
Longbow 31 Westerly
Rival 31
40.0 %
Comfort Ratio (higher = more comfortable offshore)
Spencer 31 ★
28.9
Hughes 31
Longbow 31 Westerly
27.0
Rival 31
31.9
Capsize Screening (lower = safer)
Spencer 31 ★
1.74
Hughes 31
Longbow 31 Westerly
1.80
Rival 31
1.73
Displacement / Length (lower = lighter)
Spencer 31 ★
Hughes 31
293
Longbow 31 Westerly
Rival 31
339
Hull Speed
Spencer 31 ★
6.6 kts
Hughes 31
Longbow 31 Westerly
6.7 kts
Rival 31
6.6 kts
Speed Number (higher = faster)
Spencer 31 ★
1.7
Hughes 31
Longbow 31 Westerly
1.7
Rival 31
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