Prout · Catamaran

Prout Snowgoose 37

The Snowgoose 37 is an 11.3 m cruising catamaran designed by the brothers Roland and Francis Prout and built by Prout Catamarans on Canvey Island, Essex: from 1978 as the successor to the Snowgoose 35, from 1986 as the Snowgoose 37 Elite, a foot wider (4.95 instead of 4.76 m) with bigger aft cabins, and from 1995, when Prout dropped its model names, simply as the Prout 37. Prout recorded its 400th delivery in 1996; SAILING Magazine later put the total at around 500. Typical of the design are the mast stepped well aft with a small mainsail, a big genoa and a staysail, the long central nacelle, and a single diesel driving a steerable outdrive leg that lifts clear of the water under sail, made by Sillette (the brochure of about 1983 calls it a Sonic leg); twin engines on saildrives were an option. The standard engine changed over the years, from a 22 hp three-cylinder Yanmar around 1983 to a 27 hp Yanmar on the Elite and a 30 hp fresh-water-cooled diesel on Prout’s website of 1997 to 2002, and many boats have been re-engined since, so read the engine plate before ordering parts. Prout Catamarans went into administration in September 2001; what remains are scanned brochures, Prout’s archived web pages and Sillette’s handbook and spares for the drive leg.

Manuals & documents

Prout Catamarans went into administration in 2001 and no longer exists, and we found no owners’ association that publishes the builder’s papers. The two brochures are scans kept by the catamaran website katamarans.com (unofficial copies), Prout’s own web pages of 1997 to 2002 survive on archive.org, and the handbook and spares list for the drive leg come from its maker, Sillette Sonic. We host no manuals or brochures.

Marked “unofficial copy”: the maker publishes no manual for this model any more, so the link goes to a third-party copy. Prefer the maker’s or a dealer’s version if you can get one.

Equipment & its manuals

Standard equipment as the builder’s documents list it. Boats were ordered with options and refitted since — check what is actually aboard.

ItemModelManual / pageNote
EngineYanmar, 3 cylinders, 22 hp1Standard in the brochure of about 1983, with gearbox and 2:1 reduction, driving the Sonic leg; 6 to 8 kn on ⅓ to ½ imperial gallon an hour—The brochure gives no type designation; many boats have been re-engined, so check the plate.
EngineYanmar, 3 cylinders, 27 hp2Standard on the Elite: raw-water cooled with a 2:1 gearbox in the standard specification, while the brochure’s text and table call it fresh-water cooled—Prout names no type. Yanmar’s 27 hp three-cylinder of those years is the 3GM30 (raw water) or 3GM30F (fresh water), both on our page; check the plate. Cooling water comes in through a Vetus strainer, and the exhaust leaves through a rubber silencer and a skin fitting in the nacelle transom.
EngineDiesel, 30 hp, fresh-water cooled3,4Prout’s website of 1997 to 2002 (Prout 37); make not named—
EngineTwin diesels on saildrives (option)1,2Brochure of about 1983: other engines up to a twin-engine motor-sailer; Elite brochure: twin engines on saildrives, 12 to 14 kn depending on the engines—
SterndriveSonic leg (Sillette)1,2,5,6Brochure of about 1983: ‘Special Sonic Leg’; Elite: a steerable outdrive leg commissioned by Prout, with reverse lock and its own steering lever, lifted clear of the water under sailSillette: Sonic Catamaran Drive Mk 2 owner’s handbook (scan)Sillette’s Mk 2 catamaran drive dates from 1979, works with the engine’s own gearbox and names Prout’s ready-made engine pod; the drives are no longer made, but Sillette still sells spare parts.
Propeller3-blade, 14 × 11 in · 14 × 14 in1,2,514 × 11 in in the brochure of about 1983; 14 × 14 in in the Elite’s standard specification—Sillette fits three-blade propellers of 13 to 16 in on shafts with 12 or 17 splines; check which shaft your leg has.
SteeringHydraulic, twin GRP rudders1,2,7Hydraulic in both brochures; on the Elite the rudders hang on a stainless upper gudgeon and lower pintle with nylon ball fittings, and the leg is steered by a separate single lever—SAILING Magazine: wheel on the bulkhead to starboard; two transom-hung rudders on the original 37, smaller rudders below the waterline on the Elite.
WinchesLewmar, 2-speed self-tailing × 22Elite standard specification: two Lewmar two-speed self-tailing sheet winches ‘or similar’, with handles—
Mast & riggingAluminium, 6.6 × 5.2 in, 40 ft2,1Elite: anodised mast with spreaders, masthead tricolour and spinnaker-boom track; boom 80 mm × 10 ft 6 in with slab reefing; 1 × 19 stainless rigging of 8 mm with roll-swaged terminals and 7/16 in rigging screws, eight chainplates; Barton mainsheet traveller. Brochure of about 1983: the mast stands in a tabernacle for lowering—
FurlerHeadsail roller furling2Elite standard specification; make not named—
SailsTerylene 8 oz: main, genoa, staysail2Elite: mainsail of 201 sq ft with two reefs, genoa of 400 sq ft, staysail of 95 sq ft, mainsail cover—
Hatches & ports5 aluminium deck hatches · 10 mm tinted windows2,1Elite: five opening aluminium hatches (three small, two large) and tinted 10 mm Plexiglas windows with two opening ports; the brochure of about 1983 mentions extra hatches and a larger saloon door—
InstrumentsPlastimo compass, log, echo sounder2Elite standard specification: Plastimo bulkhead compass ‘or similar’, log and echo sounder; makers of log and sounder not named—
LightsFluorescent 8 W × 10, tricolour2Elite: ten 8 W fluorescent lights inside, masthead tricolour, navigation lights at deck level, steaming light and deck floodlight—
Batteries12 V: 90 Ah + 70 Ah engine1,2Brochure of about 1983: 100 Ah; Elite: one 90 Ah house battery and one 70 Ah engine battery with charging relay and master switch, 12 V alternator, negative earth—
StoveOptimist 3-burner hob, oven & grill1,2Brochure of about 1983: de luxe oven as standard; Elite: three-burner Optimist hob and eye-level Optimist oven and grill—
Gas system7 kg bottle, copper pipe2Elite: regulated 7 kg bottle in a vented locker, 3/8 in copper pipe to the galley—
Water heaterGas water heater2Elite standard specification: gas water heater with oxygen sensor—
Water pumpPressure pump, hot and cold2Elite: pressurised hot and cold water to galley and heads—
Bilge pumpHenderson Gusher type2Elite: bilge pumps of the Henderson Gusher type, worked from the cockpit—
ToiletMarine toilet with seacocks2Elite: sea toilet with seacocks on inlet and outlet in a moulded heads compartment with shower, forward in the port hull; make not named—
FridgeIcebox · fridge (option)1,2,7Brochure of about 1983: fridge as an option; Elite: icebox moulded into the starboard aft berth—SAILING Magazine: fridge and freezer sit under the aft-cabin berth.
Fuel systemStainless tank in the nacelle2Elite: stainless steel tank under the cockpit sole with sight gauge; fuel pump, filter and in-line sediment bowl—
AnchorCQR 35 lb · 10 m chain · 30 m warp2Elite ‘drop-in items’: CQR or similar of 35 lb, 10 m of 9.5 mm chain, 30 m of 16 mm three-strand nylon warp; heavy-duty bow roller—
Canopy & T-topPilot house or soft hood (option)1,2Brochure of about 1983: photo of the ‘Motor Sailer Option’; Elite: sturdy pilot house or soft hood as options—

Specifications

Years built1978 to 2002: the Snowgoose 37 was designed and first built in 1978, the Elite introduced in 1986 and its interior renewed in 1993; sold as the Prout 37 from 1995 and still listed on Prout’s website in December 20028,4,9
VersionsSnowgoose 37 (1978; ‘New Snowgoose 37’ with a new layout by about 1983) · Snowgoose 37 Elite (1986), a foot wider with bigger aft cabins · Prout 37 (name from 1995) · open-plan or private-stateroom layout · motor-sailer with pilot house and twin engines on saildrives as options1,2,8,3
Hulls built400th boat delivered in 1996 (Prout); around 500 in all according to SAILING Magazine (2004)8,7
DesignerRoland and Francis Prout8,10
BuilderProut Catamarans Ltd, Canvey Island (Essex, England): at The Point until August 1992, then in Kings Close; registered in 1971 as Prout Boat Services Ltd, named Prout Catamarans Ltd from 1985 and 199 AB Ltd from October 2001; built under licence in Australia from 19888,3,1,11
PredecessorProut Snowgoose 35 (1969), built under licence by Thames Marine until 19768
Length overall11.3 m (37 ft 0 in) in the Elite brochure and on Prout’s website of 1997 to 2002; the brochure of about 1983 gives 37 ft (11.56 m in its metric column)2,3,1
Waterline lengthElite 10.3 m (33 ft 11 in); 33 ft (10.32 m) in the brochure of about 19832,1
BeamElite and Prout 37: 4.95 m (16 ft 3 in), each hull 1.30 m (4 ft 3 in) at its widest; original Snowgoose 37: 4.76 m (15 ft 3 in)2,3,1
Draft0.85 m (2 ft 8 in) in both brochures; 0.8 m (2 ft 7 in) on Prout’s website of 1997 to 20021,2,3
DisplacementElite: 5216 kg (11500 lb); the brochure of about 1983 prints 2536 kg (5600 lb), less than half, so treat that figure with care2,1
KeelLow-aspect-ratio keels moulded in one piece with the hulls, which protect rudders and drive leg and let the boat dry out upright; twin rudders2,12,1
Air draftNo air draft in the builder’s papers: the mast stands 12.2 m (40 ft) above the deck on the Elite and 37 ft on the boat of about 19832,1
Sail areaWorking sail area 52 m² (570 sq ft) in the brochure of about 1983, including a staysail of 8 m² (88 sq ft); Elite staysail 7.8 m² (84 sq ft)1,2
Mainsail17 m² (187 sq ft) about 1983; Elite 18.5 m² (200 sq ft)1,2
Genoa35.6 m² (383 sq ft) about 1983; Elite 38.6 m² (416 sq ft)1,2
Light-air sailsSpinnaker 140 m² (1500 sq ft) in both brochures1,2
EngineAbout 1983: 22 hp three-cylinder Yanmar with 2:1 gearbox; Elite: 27 hp three-cylinder Yanmar; 1997 to 2002: 30 hp fresh-water-cooled diesel1,2,3,4
Engine optionsOther engines up to a twin-engine motor-sailer (about 1983); twin engines on saildrives with 12 to 14 kn depending on the engines (Elite)1,2
DriveOne engine in the nacelle under the cockpit driving a steerable outdrive leg that tilts out of the water under sail (Sonic leg by Sillette); twin saildrives as an option1,2,5
Cruising speed6 to 8 kn under power (both brochures)1,2
Fuel consumption⅓ to ½ imperial gallon an hour; 2½ l/h in the specification tables1,2
Fuel tank82 l (18 imperial gallons) about 1983; Elite: 68 l (15 imperial gallons) in the brochure table, ‘approximately 20 gallons’ in the standard specification, of stainless steel under the cockpit sole1,2
Water tank335 l (75 imperial gallons) about 1983; Elite: 410 l (90 imperial gallons) in two tanks moulded into the keels, which also form a double bottom1,2
CabinsElite: double cabins aft in both hulls and forward in the starboard hull, galley and chart table amidships in the hulls, heads with shower forward to port; standard open-plan saloon whose wrap-around settee converts to a double, or the private-stateroom option with a double berth forward of a bulkhead with a sliding Perspex window2,3,1
BerthsProut’s website: one king-size and two doubles, or three doubles; brochure of about 1983: three double cabins plus a double in the forward part of the saloon3,1
Berth sizesElite: aft port 208 × 149 cm, aft starboard 208 × 130 cm, forward 186 × 104 cm, saloon double 203 × 137 cm, saloon singles 198 × 61 cm2
HeadroomElite: up to 1.86 m (6 ft 1 in) in the saloon, 1.99 m (6 ft 6 in) on average in the hulls2
HullGRP: hull, bridgedeck and nacelle in one moulding together with keels and rudder fairings; deck in one piece with balsa sandwich where stiffness is needed, bonded to the hull along the gunwale and at the bulkheads; buoyancy compartments fore and aft in each hull. Prout’s website of 1999 adds hand lay-up with isophthalic resin and an end-grain balsa core above the waterline2,12

Good to know

  • Prout Catamarans Ltd has been in administration since 13 September 2001, was renamed 199 AB Ltd that October and was dissolved in November 2024, so nobody supplies the builder’s papers or parts any more. What is left: the scanned brochures with the Elite’s standard specification, Prout’s web pages of 1997 to 2002 on archive.org and, for the drive leg, Sillette Sonic Ltd in Poole, which no longer builds Sonic drives but still sells spare parts and the handbook.11,13,6,14
  • The drive leg has its own oil: Hypoid 90 only, 5 to 7 litres depending on the length of the leg, filled slowly and checked on the dipstick with the boat level. Sillette asks for a first service at 20 hours, then a check every 40 hours or every month, whichever comes first, and a weekly look at the oil; milky oil means water is getting in. The steering yoke (part 35) is meant to break first when the leg hits something, so it is worth carrying as a spare.5
  • Leg and mounting plate are aluminium: keep the anodes on the plate and around the propeller unpainted and in metal contact, and put only copper-free antifouling suitable for aluminium on the leg. Never leave the leg down where the boat dries out at low tide; tilt it. For the winter, Sillette advises draining the oil, refilling with a lay-up oil and making sure no weight of the hull rests on the leg.5
  • The Elite’s specification lists a manual reverse lock for the leg: engage it before going astern (at sea, Sillette says, before throttling back), or the leg kicks up under reverse thrust. Sillette sells kits that convert it to a single or double autolock for Prout catamarans. The propeller shaft has 12 or 17 splines depending on the unit, so check yours before ordering a propeller.2,5,15
  • To tell the versions apart: the original 37 is 4.76 m (15 ft 3 in) wide and, according to SAILING Magazine, has two transom-hung rudders, while the Elite of 1986 on is 4.95 m (16 ft 3 in) wide with smaller rudders below the waterline. Prout renewed the interior in 1993, sold the boat as the Prout 37 from 1995 and had Snowgooses built under licence in Australia from 1988, so details vary from boat to boat.1,2,7,8
  • SAILING Magazine’s buyer’s guide advises having the drive leg inspected by a mechanic who knows Sonic drives, because repairs are expensive, and looking hard at the wiring: the original was not the boat’s best feature, and most boats carry years of owners’ additions. Check the standing and running rigging and the hydraulic steering as well.7,1

Videos & how-tos

Links to YouTube, nothing embedded. The maker’s own channel comes first; the rest are channels we found clear and correct for this model.

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Sources

  1. katamarans.com/wp-content/uploads/2020/11/prout-37-snowgoose-brochure.pdf
  2. katamarans.com/wp-content/uploads/2020/11/prout_snowgoose_37_elite_brochure.pdf
  3. web.archive.org/web/19971007022344/http://www.prout-catamarans.com:80/37.htm
  4. web.archive.org/web/20021013055113/http://www.prout-catamarans.com:80/37.htm
  5. sillette.co.uk/images/pdfs/SonicCatamaranDriveMk2Handbook2012complete.pdf
  6. sillette.co.uk/products/sterndrives-and-saildrives/sonic-type-2
  7. sailingmagazine.net/article-permalink-554.html
  8. web.archive.org/web/19991013102623/http://prout-catamarans.com:80/the_company.htm
  9. web.archive.org/web/20021211085123/http://prout-catamarans.com:80/Sailing%20cats%20list.h…
  10. katamarans.com/product-tag/prout/
  11. find-and-update.company-information.service.gov.uk/company/01004653
  12. web.archive.org/web/19991013082501/http://prout-catamarans.com:80/advantages.htm
  13. find-and-update.company-information.service.gov.uk/company/01004653/insolvency
  14. sillette.co.uk/downloads
  15. sillette.co.uk/images/pdfs/sillette_%20sonic_%20parts_list.pdf

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