Pre-Purchase Survey Day: A Full Lagoon 450 F Inspection in Preveza

Yesterday’s job was a full pre-purchase condition survey on a Lagoon 450 F catamaran at Aktio Marina, Preveza. It was one of those classic winter survey days in the Ionian: cold, clear, and ideal for a proper structural inspection with the boat ashore and everything accessible. These are always the surveys I enjoy most, because they allow a vessel to be assessed methodically and without compromise.

A pre-purchase survey is not just about finding faults. It is about understanding the true condition of a yacht, separating normal age-related maintenance from genuine concerns, and giving the buyer a clear, realistic picture of what ownership will involve. With larger cruising catamarans like the Lagoon 450, this process becomes even more important because of their complexity: twin hulls, twin engines, saildrives, generator, air-conditioning, large electrical systems, and extensive deck hardware.

The structure always comes first. The hulls were inspected ashore with percussion sounding and moisture meter testing. Both hulls responded well to sounding, with no dull areas or signs of delamination. Moisture readings were consistent with what would be expected for a vessel of this age and construction and showed no abnormal results. Topsides and deck mouldings were also in good condition, with only minor cosmetic wear to the gelcoat.

Bulkhead image and bondings

On any Lagoon 450 survey, there are two design areas that receive particular attention: bulkhead tabbing and the mast compression post. These are known watch-points on this model and must always be checked carefully. In this case, the bulkhead bonding and surrounding structures were found to be sound in accessible areas, and no evidence of movement, cracking, or separation was observed.

Steel mast compression post showing corrosion. This is a known issue on this model and should be closely monitored, with repair or replacement considered as part of future maintenance planning.

The compression post area was examined closely for corrosion and load transfer integrity, as this is a high-stress structural component that carries the mast loads into the hull structure. These checks are critical and form a core part of any professional Lagoon 450 inspection.

Steering systems were another key focus. On multihulls, steering loads are high and transmitted through pulleys, cables, and hull fixings at the aft ends of the hulls. Small gelcoat cracks were noted around some of the pulley fastenings externally, but internal backing pads were substantial and appeared intact, meaning this was assessed as cosmetic rather than structural. There was also light corrosion at the top of the starboard rudder stock where the tiller lever joins, most likely caused by water ingress from the emergency steering hatch above. This is a straightforward maintenance item but important to address before corrosion progresses.

On some Lagoon catamarans, including the 450, owners choose to fit stainless steel load-spreading plates at the steering pulley fixing locations where the pulleys are through-bolted through the aft ends of the hulls. These areas carry high cyclic loads from the steering system, especially under heavy weather, manoeuvring, or when the rudders are working hard.

Underneath the boat, the saildrives were inspected. The owner advised that the saildrive seals had been replaced recently, subject to documentation. A visible gap was noted between the propeller boss and propeller on both units, which is usually an adjustment issue rather than a fault with the saildrive itself. These are typical findings that fall into recommissioning rather than major defect territory.

One of the most important parts of this survey day was the machinery inspection. Independent marine engineers were present to carry out compression testing on both engines, which is always good practice on a pre-purchase survey. Both engines recorded compression figures that were confirmed as being within acceptable limits by the engineers, providing strong reassurance on the internal mechanical condition of the engines. This is a valuable piece of information for any buyer and removes much uncertainty.

Compression tests were carried out and the results were generally around 30 PSI, which were confirmed as being within acceptable operating limits. Factory reference figures are approximately 35 PSI.

The generator inspection revealed a more significant maintenance issue. After removing the hush cover, corrosion was clearly visible on the drip tray, with some extending into the generator mountings and light corrosion on the underside of the unit. This is typical of long-term moisture exposure and usually points to a small raw-water leak somewhere in the cooling system. This is not unusual, but it must be addressed properly: leak source identified, corrosion treated, and the tray cleaned and repainted with a proper anti-corrosive coating.

Electrical systems on this yacht were well specified. The boat benefits from upgraded domestic batteries, solar panels mounted on a substantial stainless arch, a modern MPPT solar controller, and a generator. The electrical installation was tidy and well laid out, with RCD protection for the shore power system and clearly identified breakers for high-load equipment such as the genoa winch and davits. This is exactly what you want to see on a cruising catamaran.

Freshwater systems were tested and found to be working correctly. Two blue polyethylene tanks were fitted, a calorifier was installed below the starboard aft berth, and the system pressurised and delivered water as expected. A watermaker was listed and identified onboard, though like many systems, it requires operational testing under load to confirm full performance.

A small but important detail was the presence of fresh water in the port midships bilge. The source was not immediately identifiable and could originate from plumbing, deck fittings, air-conditioning condensate, or incidental ingress. This is a classic example of something that is not serious in itself, but absolutely must be traced and resolved to prevent long-term damage.

Deck fittings were generally secure, but a hose test on the forward mooring cleats showed that water was dripping through the fastenings. This means the cleats need to be removed, dried, and properly re-bedded. This is routine boat maintenance, but it is exactly the kind of detail that a survey is designed to uncover.

Gas systems were visually inspected, including the locker, pipework, and appliances. No gas was onboard at the time, so full testing was not possible. The cooker requires servicing, including attention to flame failure devices and damaged ignition components. Again, a normal recommissioning task, but one with clear safety implications.

Safety equipment was present, but as always, service dates and certification must be confirmed by the buyer. Fire extinguishers were in good condition with gauges in the green, and engine bay extinguishers were fitted. Life-saving equipment should always be treated as “verify and service” during a purchase process.

What stood out on this job was the teamwork. Good brokers, cooperative owners, independent engineers carrying out compression testing, and buyers engaged in the process. That is exactly how professional pre-purchase surveys should be done. Everyone benefits from transparency and proper inspection.

Overall, this Lagoon 450 F was a solid example of the model. No major structural defects were identified. The findings were largely centred on maintenance and recommissioning: generator corrosion, deck fitting leaks, bilge pump restriction, small steering corrosion areas, minor electrical and lighting faults, and general system servicing. These are normal for a cruising yacht of this size and age and should be expected rather than feared.

A good survey is not about perfection. It is about clarity. By identifying known model-specific watch points, inspecting the real condition of the vessel, and separating minor issues from serious concerns, the buyer is given confidence and negotiating strength. That is the purpose of a proper pre-purchase condition survey.

Cold day, long hours, but exactly the kind of inspection that protects buyers and keeps standards high in the yacht market.

If you have your eye on a multihull in the Preveza area drop me an email to steventruss1@aol.com