Expert Assessment of Marine Refits and Modifications
Naval refit and modification assessment provides a technical evaluation of structural alterations, system upgrades, and weight modifications in recreational craft, yachts, and commercial vessels.
In Spain, any modification affecting the hull structure, vessel stability, or installed propulsion power requires technical verification in accordance with applicable maritime regulations, ensuring structural safety and administrative validity before the Spanish Maritime Authority.
Engine Replacements and Propulsion System Modifications
Engine modifications may directly affect:
Installed power
Weight distribution
Center of gravity
Transverse stability
Structural stresses on engine foundations
The technical assessment verifies the structural compatibility of the new propulsion system and its compliance with applicable maritime standards.
Structural Alterations
Structural modifications may include:
Hull modifications
Installation of reinforcements
Alterations to the deck or superstructure
Replacement of structural components
Opening or closing of spaces
Structural analysis determines whether the modification maintains hull integrity and required safety margins.
Weight and Load Distribution Modifications
Changes in weight distribution may alter:
Initial stability (GM)
Dynamic vessel behavior
Longitudinal trim
Reserve buoyancy
Expert evaluation verifies whether the changes negatively affect vessel stability and whether an additional stability study is required.
Technical Legalization and Regulatory Compliance
Following a modification, it may be necessary to:
Prepare a Technical Naval Project
Issue an expert report
Demonstrate compliance with Spanish maritime regulations
Complete the legalization procedures before the Maritime Authority
The expert report serves as the technical basis for administrative regularization, preventing regulatory issues.
Scope of Application
Refit and modification assessment applies to:
Recreational craft
Yachts and megayachts
Commercial vessels
Administrative regularization processes
Each case requires a specific technical evaluation depending on the vessel type and scope of modification.
Technical and Legal Assurance
The expert report must be:
Technically substantiated
Based on Naval Engineering principles
Clearly and objectively drafted
Defendable before official authorities
Technical robustness ensures both structural safety and legal protection.
NAVARCHIT – Naval Architecture and Marine Engineering in Spain
© 2026 VALENCIA Marine Services


Chartered Naval Architect and Marine Engineer in Spain with more than 20 years of experience in technical naval projects, structural inspections, maritime expert reports, and vessel stability analysis for commercial shipping, yachts, and recreational vessels across Spain.
Naval Architecture Services
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Technical Naval Projects
Maritime Expert Witness Reports
Stability Studies
Structural Analysus
Vessel Legalization
Naval Architect in Spain
Valencia
Barcelona
Tarragona
Castellón
Alicante
Palma
Cartagena
Madrid
Oficina: Real Club Náutico de Valencia
Phone: +34 96 13 050 13
Mobile: +34 644 70 90 38
E-mail: info@navarchit.com
Chartered Naval Architect in Spain specialized in Technical Naval Projects, Stability Studies, Structural Inspections and Maritime Expert Witness Services.
