1987 GUY COUACH Motor Yacht JUSTINE: 97' (29.57m) Vintage Luxury

M/Y Justine — 100' Custom Motor Yacht

Custom Interior & Entertainment Spaces

Justine offers a rare blend of elegant design and customizable functionality. Thanks to modular furniture throughout, the yacht’s interior and exterior spaces can be easily adapted for entertaining, relaxation, or charter use with minimal effort or cost.

The flybridge features expansive seating centered around a marble fireplace, which becomes the centerpiece for evening gatherings. The area is furnished with imported pieces from Spain and highlighted with custom lighting. This space can comfortably accommodate 25+ guests, with ample seating for all.

On the main deck, you'll find a massive galley—perfect for both private use and professional chefs—alongside a spacious main salon. The salon includes a bar, formal dining, and lounge area, offering an inviting setting for entertaining or family use.

Accommodations

Below deck, Justine comfortably sleeps 8 to 10 guests across four staterooms plus a flexible adjoining cabin, ideal for children or staff.

• Master Stateroom:

  • Full-beam layout

  • "His and hers" en suite heads connected by a shared tub

  • Excellent opportunity for conversion to a modern walk-through rain shower

• VIP Stateroom:

  • King berth

  • En suite head

  • Adjoining fifth cabin with two bunks and its own full ensuite head—ideal for young children

• Guest Cabins (Port & Starboard, Midship):

  • Twin berths in each

  • Full en suite heads

• Crew Quarters:

  • Two berths

  • Full en suite head

  • Spacious and well-separated from guest accommodations

Mechanical & Performance

Justine’s meticulously maintained engine room is a standout feature, reflecting the high standards of care and upkeep this vessel has received.

She is powered by twin Detroit Diesel 12V92TI turbocharged engines, which, paired with a lightweight Kevlar-over-balsa core hull, offers efficient cruising at 11 knots and a top speed of 20 knots. Every aspect of the vessel—mechanical, structural, and cosmetic—has been consistently maintained to professional standards, ensuring minimal downtime.

Engine & Generator Details

Main Engines – Detroit Diesel 12V92TI

• Full zero-hour rebuilds completed in 2005

• At time of sale to current owners in 2009, engines had 354 hours

• Comprehensive maintenance records from 2009–2025 are available

Ongoing Maintenance:

• Oil and filters changed every 150 hours using factory-spec products

• Engines regularly operated at high RPMs to prevent carbon buildup and lubricate turbochargers

• Engine room kept heated during cold months to avoid cold starts

Major Engine Service (2021) – Florida Detroit Diesel, Fort Pierce:

• Full gasket replacement

• Heat exchangers, blowers, and aftercoolers cleaned

• Valve, injector, and governor adjustments completed

Generators – Northern Lights

• Major Service (2023):

  • All gaskets and injectors replaced

  • Cooling systems serviced

  • Units fully repainted

• Oil and filters changed every 150 hours using factory-spec products

Recent Upgrades & Maintenance

• 2025 (February):

  • Injector replacements, valve adjustments, and engine tuning completed

• 2024:

  • Installed new Vetus 320 48V brushless bow thruster (10", electric), replacing previous 8" hydraulic unit

• 2023:

  • Upgraded to new Glendinning throttle and transmission controllers

• July 2024 (Haul-Out):

  • Bow thruster installation

  • Full routine haul-out service including:

    • Bottom paint

    • Running gear inspection

    • Zinc replacement

    • Propeller service

Build History & Provenance

• 1987:

  • Hull laid in France, built for export

  • Interior completed in Dania Beach, Florida

  • Originally constructed as a 90-foot hull, without a swim platform

• 1987–2009:

  • Privately owned by two meticulous owners

  • Maintained to high personal standards

• 2005:

  • Extensive refit performed

  • Swim platform added (LOA extended to 100')

  • Main engines underwent complete zero-hour rebuilds

• 2009–2011:

  • Comprehensive rebuild including:

    • All new interior, helms, galley, plumbing, electrical, and lighting systems

• 2011–Present:

  • Operated as a high-end private charter yacht in New York City and New England

  • Professionally maintained fleet vessel

  • Ongoing cosmetic and systems upgrades to meet luxury charter standards

• 2016:

  • Installed (8) 4" thru-hull underwater lights

• 2020:

  • Major updates including:

    • Nuteak synthetic decking

    • Full Imron paint job to yacht-standard finish

    • During paint process, all railings, windows, and thru-hulls were removed

    • Balsa core inspected with moisture meter; any compromised areas replaced with honeycomb or solid PVC

    • Confirmed bone-dry hull core

Conclusion

Justine is one of the finest examples of a classic 100' motor yacht on the market today. With a robust build, tasteful upgrades, and an exceptional maintenance record, she offers turn-key readiness for both private cruising and charter service.

Whether you're looking for a luxurious private vessel or a proven charter performer, Justine stands out for her condition, flexibility, and pedigree.

All service records, maintenance logs, and operational documentation are available and up to date.