Blount Marine 47.85m Steel Expedition Yacht 1978 (2015 Refit) Heli-Pad US Flag Golfito Costa Rica

Overview
Delivered in 1978 by Blount Marine and extensively refitted in 2015 by Merril-Stevens, this 47.85-metre steel expedition yacht is a true long-range explorer platform built for endurance, autonomy and serious ocean travel. Designed by Kirilloff and Associates, she was conceived as a capable full-displacement vessel—prioritizing stability, storage and global passagemaking rather than seasonal coastal use—making her a rare acquisition opportunity for buyers who want real range, steel strength, and expedition functionality.

Construction, Hull Form & Expedition Credentials
Constructed entirely in steel for both hull and superstructure, she delivers the structural integrity, durability and impact resistance highly valued in expedition-class yachts. She measures 47.85m LOA with 41.92m waterline length, a substantial 10.7m beam, and 3.0m draft, contributing to a formidable displacement of approximately 640 tonnes and an internal volume of 284 GT. The full-displacement hull form provides excellent seakeeping, predictable motion, and efficient operation at moderate speeds—ideal for long passages through varied sea conditions.
Her beige hull and white superstructure are arranged across three decks with steel deck construction, and a flybridge configuration that improves visibility and operational command. A dedicated heli-pad is integrated into the design, expanding logistics capability for remote cruising and reinforcing her explorer pedigree. She is registered under the United States flag, reflecting commercial-grade construction standards adapted for private yacht operation.

Propulsion, Speed & Exceptional Range
Powered by twin General Motors 12V149 diesel engines producing 650 hp (872 kW) each—1,300 hp (1,744 kW) combined—she drives twin screw propellers through conventional shaft lines engineered for reliability and straightforward maintenance, including in remote regions. Performance targets endurance and safety: 11 knots maximum and 9 knots cruising, with an exceptional range of approximately 12,000 nautical miles at 10 knots.
Autonomy is a defining asset. Fuel capacity is an extraordinary 336,900 litres, enabling extended voyages with minimal dependence on refuelling ports. Freshwater capacity is 28,390 litres, further supporting long-range programs and remote-area operations.

Engineering Systems & Operational Practicality
Heavy-duty shafts, couplings and stern tube assemblies are designed for endurance duty cycles, supported by a balanced rudder configuration for steady helm response. The engine room layout prioritizes accessibility with clear service pathways, visible engine data plates, organized fuel filtration systems, cooling circuits and durable exhaust routing. Electrical generation supports hotel loads via integrated generator systems, distribution panels, breakers, battery banks and shore power connectivity. Plumbing infrastructure includes freshwater pumps, bilge systems, hot water supply and holding tank arrangements suited to extended operational needs.
Safety systems include machinery-space fire suppression, portable extinguishers, and verified navigation instrumentation. The steel hull below the waterline is protected by professional-grade coatings and antifouling systems, while underwater appendages are engineered for resilience across diverse cruising environments.

Guest & Crew Accommodation
Accommodation is arranged for up to 12 guests in 6 suites, supported by 14 crew in 6 crew cabins including a dedicated captain’s cabin. The significant crew capacity is consistent with her expedition heritage, enabling full-service capability for extended voyages and specialized operations. The interior configuration balances comfort with practicality, offering substantial communal areas for relaxation, dining and social engagement across a stable three-deck platform.

Deck Areas, Utility & Adaptability
Exterior deck areas provide expansive working and leisure zones, with the flybridge enhancing both command visibility and outdoor enjoyment. The heli-pad adds meaningful versatility for remote access, emergency logistics or executive transport. Open deck spaces can be adapted for expedition equipment, additional tenders, dive operations support, scientific missions, or “mothership” roles where storage and endurance matter more than seasonal glamour.

Refit History & Acquisition Notes
The 2015 refit by Merril-Stevens represents documented investment in upgrades and continued operational relevance. As a U.S.-flagged vessel, registration and compliance considerations depend on the purchaser’s intended cruising grounds and operational profile, with tax and import obligations varying by jurisdiction. Buyers are strongly encouraged to proceed with a comprehensive survey and sea trial to evaluate hull condition, machinery, electrical infrastructure and onboard equipment. The standard sale process typically includes a written offer with escrow deposit, due diligence, survey completion, negotiation of findings, and closing under recognized yacht sale agreements. Onboard equipment, machinery and installed systems are included in the sale unless otherwise agreed.

Key Specifications at a Glance

• Builder: Blount Marine | Delivery: 1978 | Refit: 2015 (Merril-Stevens)
• Designer: Kirilloff and Associates
• LOA: 47.85m | LWL: 41.92m | Beam: 10.7m | Draft: 3.0m | GT: 284 | Displ.: ~640 t
• Construction: Full steel hull & steel superstructure | Hull Form: Full displacement
• Engines: 2 × GM 12V149 (650 hp each) | Drive: Twin screw / shafts
• Max Speed: 11 kn | Cruise: 9 kn | Range: ~12,000 nm @ 10 kn
• Fuel: 336,900 L | Freshwater: 28,390 L
• Guests: 12 in 6 suites | Crew: 14 in 6 crew cabins + captain
• Features: Flybridge, heli-pad, expedition utility deck spaces
• Flag: United States | Location: Golfito, Costa Rica

Call to Action
For a full expedition-capability brief, refit records, and to arrange a survey and sea trial in Golfito, contact KaterBlue Marine Services. If your goal is true global range with steel-hull resilience and heli-pad logistics—this is the kind of platform that rarely comes to market in this size bracket.