Catalac 8M, the Pocket Catalac With the Biggest Cockpit
Tom Lack cut a little off each end of the 9M hulls and created a 27 ft catamaran that sailed livelier, cost less and still crosses seas.
- Length
- 27 ft8.23 m
- Beam
- 13.7 ft4.17 m
- Draft
- 2 ft0.61 m
- Cabins
- 1 double cabin forward plus single berths in the hulls
- Used price
- $18K to $42K
On this page
- Overview
- How the Catalac 8M was cut from the 9M
- Lighter than its big sister, and livelier for it
- The largest cockpit of any Catalac
- Outboard pod or twin Yanmar 1GM10s
- Hurricane deliveries and Mediterranean crossings
- Buying and keeping a pocket cat for the price of a car
- Specifications
- Price and value
- Strengths and weaknesses
- Used buyer checklist
- Rivals
- Our verdict
- FAQ
The Catalac 8M (Catalac 27) is a 27 ft British pocket cruising catamaran built by Tom Lack Catamarans at Christchurch from the mid-1970s. Around 216 were built on shortened 9M hulls, and about 40 are thought to be in the Americas.
- Couples or small families on a tight budget
- Florida, Bahamas and ICW gunkholing
- Canal and river cruising with a lowering mast
- First-time catamaran owners
Catalac 8M by the numbers
- Sail area to displacement
- 12.9A cruising rig sized for comfort, so expect to motor in very light air.
- Displacement to length
- 169Light displacement for its length, quick but sensitive to added cruising weight.
- Theoretical hull speed
- 6.8 knDisplacement hull speed for the waterline. Light catamarans regularly sail faster than this because their slim hulls do not make a large bow wave.
- Length to beam ratio
- 1.98 : 1Catamaran overall proportions. Wider platforms resist pitching and heel.
How the Catalac 8M was cut from the 9M
The Catalac 8M started as a recipe, and Practical Boat Owner's Jim Andrews spelled it out when he sailed the new boat after a September boat show: take the 9 m Catalac, finely chop a little off both ends to get 27 ft instead of 29 ft 3 in, and mix in the compact accommodation Tom Lack had developed in the old Bobcat. The result used the same hulls as the 9M, which CatamaranSite confirms, but the cabin molding is shorter and the stepped sheer of the 9M is gone, replaced by a straight sheer rising gently from stern to bow.
Sailboatdata lists 1975 as the first year and 212 built; CatamaranSite counts 216, mostly between 1975 and 1987, and estimates 41 are in the Americas. One American owner told CatamaranSite he bought his Catalac 27, the US name for the 8M, in 1977 and kept it twenty years. Many of the boats now in North America were sailed there from Britain.
Lighter than its big sister, and livelier for it
Being shorter and lighter, the 8M floats higher than the 9M and draws about 2 ft, roughly three inches less. Andrews sailed it in Christchurch Bay against an equally lightly loaded 9M, both with outboards, and found the 8M gradually overhauled the bigger boat to windward, pointed a little higher thanks to its slightly higher aspect rig and felt faster off the wind, at the cost of a little more leeway in the puffs. Its working sail area is a modest 275 sq ft.
Interestingly, Andrews found the 8M heaved to well, lying quietly with the helm down and little leeway, while a later PBO test of a 9M found that boat reluctant to heave to. CatamaranSite's owner data suggests 6 knots in 10 to 12 knots of wind and useful sailing to about 35 degrees apparent. Nobody will mistake it for a racer, but it is not the floating box its looks suggest.
The largest cockpit of any Catalac
Because the 8M's cabin is shorter than the 9M's, the cockpit is bigger, and CatamaranSite notes it is the largest of any Catalac, including the 41 ft 12M. For a family that lives outdoors, that matters more than an extra berth. The saloon has two settee berths and a long table, with huge locker space throughout; the middle saloon windows on early boats could be lifted out for ventilation, and a big sliding hatch opens up the end of the saloon.
Below the bridgedeck, the test boat had a single bunk in the port hull, a roomy washroom in the port bow and an 8 ft galley in the starboard hull leading forward to the double cabin. The factory brochure lists one double and three singles. That makes the 8M a genuine four-berth boat, where the 9M has five permanent bunks plus the saloon. An optional doghouse over the sliding hatch was fitted to most European boats and roughly 30 percent of those in the Americas; in the tropics it is less welcome.
Outboard pod or twin Yanmar 1GM10s
The brochure 8M came with a 25 hp outboard, and Andrews's test boat had a 28 hp Yamaha long-shaft slung in a pod under the after part of the cockpit, behind a cowling that let it tilt clear for sailing. With it the boat reversed through a crowded show berth with eleven adults aboard and cruised at about 6 to 7 knots. The drawback is that the outboard is not linked to the steering, so docking takes practice.
The alternative is a pair of Yanmar 1GM10 single-cylinder diesels on shafts with 2.13:1 reduction, props just ahead of the rudders. Diesel boats lose a little sailing speed to drag but maneuver on the throttles, charge batteries better and, CatamaranSite says, can motor close to 1,000 km on their tanks. One owner recorded a top speed under power of 6.5 knots on his twin-diesel 8M. Expect to pay about $10,000 more for a diesel boat in comparable condition.
Hurricane deliveries and Mediterranean crossings
The CatamaranSite webmaster bought his 8M in Florida in 2005 and spent the delivery fighting 7 knot currents on the Okeechobee waterway and then running north up the ICW ahead of Hurricane Katrina in gusts of 50 mph, reporting that the boat stayed level and stable throughout. In Europe the 8M Dunja III crossed 780 nautical miles of the Mediterranean from Leros to Malta through the edges of Storm Daniel, with winds up to 54 knots, though her crew had to be towed in after a rudder failure.
Those stories sum up the 8M fairly. The hull and rig are tough, and the boat looks after its crew, but these are boats approaching fifty years old and their rudders, steering cables and windows need proper attention before anything ambitious.
Buying and keeping a pocket cat for the price of a car
A 1986 8M listed in Lake Worth, Florida, in 2026 at $30,000 shows where the market sits. Outboard boats needing work start below $20,000, and refitted twin-diesel boats with new sails, solar and resealed windows reach the low $40,000s. A 13 ft 8 in beam fits many slips designed for monohulls, the boat dries out upright for scrubbing, and annual costs of $4,000 to $10,000 in the US are realistic for a mooring or modest slip, insurance, bottom paint and engine service.
The mast is cabin-stepped in a tabernacle and can be lowered single-handed, which opens up canals, rivers and low bridges. CatamaranSite publishes owner instructions for the job, a good example of the support the small but loyal Catalac community still provides.
Catalac 8M specifications
| Length overall | 27 ft8.23 m |
|---|---|
| Waterline length | 25.5 ft7.77 m |
| Beam | 13.7 ft4.17 m |
| Draft | 2 ft0.61 m |
| Displacement | 6,283 lbs2,85 kg |
| Sail area | 275 sq ft25.6 m² |
| Fuel capacity | 2 gal76 L |
| Fresh water | 7 gal265 L |
| Cabins | 1 double cabin forward plus single berths in the hulls |
| Berths | 4 (1 double and 3 singles in the brochure), saloon settees convert |
| Heads | 1, in the bow of one hull |
| Standard engines | Single long-shaft outboard of about 25 to 28 hp in a pod under the cockpit |
| Optional engines | Twin Yanmar 1GM10 diesels on shafts |
| Cruise speed | 6 knots |
| Hull type | Chined catamaran hulls with deep V forward, rocker and no keels (shortened 9M hulls) |
| Keel | None; twin rudders, with skegs on later boats |
| Rig | Masthead sloop on a tabernacle mast; main, working jib and 170 percent genoa supplied |
| Hull construction | Solid fiberglass hulls; cored cabin and deck |
| Builder | Tom Lack Catamarans Ltd, Christchurch, Dorset, United Kingdom |
| Naval architect | John Winterbotham |
| Other design credits | Tom Lack |
| Production | 1975 to 1987 |
| Status | Discontinued |
Figures come from builder documentation and independent tests where available. Displacement is usually quoted light, so a loaded cruising boat will weigh more. Compare these specs with another model.
How much does a Catalac 8M cost?
In mid-2026 a 1986 Catalac 8M was listed by its owner in Lake Worth, Florida, at $30,000, close to the $35,000 median of 17 Catalac 8M sales on CatamaranSite's records. CatamaranSite estimates that twin diesels add about $10,000 to a used 8M compared with an outboard boat. Window resealing, rudder condition and sails count for more than age, because the whole production run shares the same basic hull and build.
Estimate your yearly cost
A planning estimate using common rules of thumb: insurance near 1.5 percent of value, maintenance near 3 percent, haul out and bottom paint by length. Your marina, region and use will move these numbers. Open the full cost calculator.
Versions and options
- Outboard 8M
- Single long-shaft outboard in a cockpit pod; simplest, lightest and slightly faster under sail.
- Twin-diesel 8M
- Two Yanmar 1GM10 inboards on shafts; better maneuvering and charging, worth about $10,000 more used.
- Doghouse option
- A raised doghouse over the sliding hatch, common in Europe and on about 30 percent of American boats.
- Catalac 27
- The name commonly used for the 8M in the US market; it is the same boat.
Catalac 8M timeline
- 1971The Catalac 9M is introduced, providing the hulls the 8M would later use
- 1975Catalac 8M production begins at Christchurch, Dorset
- 1977Early American owners take delivery of Catalac 27s
- 1987Most 8M production completed, at about 216 boats
- 2026A 1986 8M is listed in Florida for $30,000
Strengths and weaknesses
What owners like
- Biggest cockpit of any Catalac
- Stable, upright sailing and a strong safety reputation
- Livelier than the 9M under sail
- Very shallow draft and the ability to dry out
- Mast lowers easily on its tabernacle
- Low purchase and running costs
What to weigh up
- Only four berths and limited headroom in the saloon
- Outboard boats can be awkward to dock
- Modest windward ability and leeway in gusts
- Ageing windows, rudders and steering systems
Used Catalac 8M buyer checklist
Take this list to a viewing. Your ticks are saved in this browser so you can come back to it.
Always commission an independent marine survey and an engine survey before you buy. How a marine survey works.
Rivals to consider
Catalac 9M
Same hulls with a longer cabin, more berths and a smaller cockpit; usually a little more expensive.
Compare side by sideGemini 105Mc
Bigger American cat with standing headroom and centerboards, at roughly double the money.
Compare side by sideHeavenly Twins
Contemporary British 27 ft cruising cat with a center cockpit and an offshore pedigree.
Aristocat
Robin Musters design built in Christchurch next door to the Catalacs, with a similar layout and emphasis on accommodation.
Our verdict on the Catalac 8M
The Catalac 8M is one of the cheapest ways to own a seaworthy cruising catamaran, and it does not feel like a compromise when you are sitting in that enormous cockpit at anchor in water far shallower than the monohulls around you can reach. It is a four-berth boat, it will not point like a modern cat and every example now needs its windows and rudders looked after. If you accept that, a well-sorted 8M with twin diesels is a delightful, forgiving pocket cruiser that costs less to keep than many trailer boats.
Catalac 8M questions answered
How much is a Catalac 8M worth?
Most sell between about $18,000 and $42,000. A 1986 boat was listed in Florida at $30,000 in 2026, and twin-diesel boats bring roughly $10,000 more than outboard boats.
Is the Catalac 8M the same as the Catalac 27?
Yes. Catalac 27 is the name often used in the US for the 8M.
How many Catalac 8Ms were built?
About 212 to 216, most between 1975 and 1987, according to sailboatdata and CatamaranSite.
What engines does the Catalac 8M have?
Either a single long-shaft outboard of about 25 to 28 hp in a cockpit pod or twin Yanmar 1GM10 diesels on shafts.
Can you sleep four on a Catalac 8M?
Yes. The brochure lists one double and three single berths, and the saloon settees add space for guests.
More sailing catamarans to explore
Catalac 9M
Sailing Catamarans, 30 ft
Used $28K to $55K
Broadblue 346
Sailing Catamarans, 34 ft
Used $240K to $360K
Gemini 105Mc
Sailing Catamarans, 34 ft
Used $60K to $150K
Catalac 10M
Sailing Catamarans, 34 ft
Used $55K to $100K