Yacht Survey - Sea Trials

Sea Trials make up an important part of purchasing a yacht. They allow the surveyor to inspect and understand how a vessel, and all its various parts therein, behave in 'real world' conditions, that is, to inspect how the vessel functions and performs afloat and underload in a dynamic environment. There are many parts of the vessel that simply cannot be inspected holistically while ashore in the boat yard, such as the function of the engine(s), water tightness of the stern gear, operation of the steering gear, sail shape inspection and security of the rigging.

Sea Trials may be requested by the purchaser, or recommended by the surveyor. They should be carried out, in the surveyor's opinion, once a complete out of water survey inspection has been completed, and with the hull freshly jet washed and clean. This way the vessel is ready to be fully tested, having already been checked for obvious issues that would affect performance, such as damaged propellers or a fouled hull.

The duration of yacht sea trials can vary, and depend on the complexity of the vessel, and the issues that the surveyor may discover. What is important is that each component related to the sea trial is inspected and fully tested during that time. This includes:

Engine's functionality and operation at running temperature
- With laser thermometer testing equipment we meticulously check the temperature of each part of the engine, inspecting for heat spots that may be related to blockages, incorrect fuelling, lubrication or coolant issues, or any other such fault which we would then study and report on.
- We visually inspect the engine(s) before, during and after the sea trial, and record what changes may have been inspected. This typically relates to clues that are suggestive of leaks, corrosion, heat spots, misalignment, or poor maintenance.
- All engine functions including starting, stopping, gear selecting and throttle are checked and rechecked to ensure their function is a) reliable and b) satisfactory.
Inspection of DC electrical system including alternator operation and charging system
Stern gear and packing gland function
- Inspecting for multiple important yet subtle faults including ingress, wear, corrosion, vibration, loading, alignment, maintenance, and more, while these parts are operational and underload.
Steerage under load
- Inspection of steering equipment, loading points and function of the steering system with the weight of the sea against the rudder face(s). This is something that simply cannot be tested with a vessel ashore.
Water tightness of seacocks and valves
- This simply cannot be done ashore. Such parts are inherently important with regard to the seaworthiness of the vessel.
Testing generators
Testing bow and stern thrusters
Testing transducer and speed log equipment for functionality and accuracy
Testing GPS and AIS equipment dynamically
Integrity/ stiffness of the hull
- This is the surveyor's best opportunity to asses the structural integrity of the hull. A sharp surveyor with extensive vessel construction knowledge should carefully assess the hull for panting, canting and levering across laminates and around structural members.
Testing vessel manoeuvrability both in tight quarters and in open sea.
- All elements that drive and manoeuvre the vessel are considered holistically, along with vessel's load and trim, an issue often overlooked, with heavily loaded sterns.

..... And specifically for sailing yachts....

Inspection of sail shape and balance on the helm
- Depending on the conditions we take the opportunity to inspect, test and trim each sail on each tack.
Testing of furling equipment
- A linchpin of sailing yacht safety, and yet an often overlooked component, rarely inspected and seldom serviced. Carefully assessing the function of furling equipment is paramount.
Security and tightness of standing rigging and chainplates
- Inspection and assessment of rig tension and rigging attachment points when under sail both on the windward and leeward side.
Condition of running rigging
- Inspecting for stretch, slip, chafe points and wear when the rope is loaded.
Inspection of winches and blocks
- Testing for functionality and security underload.