A sea trial is usually conducted as part of every Pre-purchase survey and included in the quoted price- not an extra cost.
The best way to describe it is to compare to buying an automobile. You would expect to take a test drive with a trusted mechanic to
identify problems, if any, and get a feel for the way the vehicle handles. During a sea trial, the captain at the helm of the vessel is
responsible for safe navigation and the general safety of everyone on board. The captain should be familiar with the vessel and an
experienced seaman. This task is usually assigned to the boat's owner or the broker involved who usually has their Master's license.
The surveyor never takes the helm. The surveyor will give directions to the captain who will then carry them out when safe and legal to
do so. The typical sea trial will involve cruising the powered boat at different rpms and take readings at each level. Readings will include
speed of the vessel, engine temperature, oil pressure, battery voltage, and any other displayed information. The surveyor will expect the
captain to operate the vessel at wide open throttle if conditions permit for several minutes. The surveyor will also be moving about the
vessel while underway to observe the engines, outboards, outdrives, prop shafts, transmissions, bilges, and the cabin spaces looking
for problems. Additionally, a "dead engine" test will be performed on multi-engine installations. This entails powering up each engine
individually to wide open throttle with the other in neutral or if outboards, shut down and raised. This only lasts long enough to establish
top speed and maneuverability. It is to discover the vessel characteristics and simulate the ability to make port if this should actually
happen at sea. Additionally, it demonstrates the engines are balanced power-wise. The engines should match each others' rpm and
speed attained. The sea trial is a busy time for the surveyor and a lot to accomplish in the alloted time which is one hour.
Sailboats follow the same protocol. Time will not be given to navigate under sail. However, if rigged, the sails should be opened to
observe the operability of the sail handling equipment and to check the condition and shape of each rigged sail.
The sea trial is not the time to introduce others to your new boat. Attendees should be limited to the buyer(s), the surveyor, and
whomever is piloting the boat. Many times the buyer will ask to bring a personal advisor along and that is OK if the boat is rated for at
least 4 people. There should be all the required safety equipment aboard in operable condition including a PFD for each attendee.
Water tanks and fuel tanks should be reasonably full. Decks cleared. Loose items in the cabin safely stowed or secured. The vessel will
be pronounced ready for sea trials by the surveyor. Knowing that deck hatches and engine hatches will be open, high speed maneuvers
will be performed in all sea conditions, and the surveyor and captain should not be distracted from the business at hand, the buyer is
asked to refrain from bringing children, pets, alcohol or drugs, (or be under the influence of either). After the technical aspect of the
trial is compete, the buyer should take the helm with the captain at his/her side to get a feel for the boat.
The seller or broker, if asked, will usually take a second cruise with the buyer's family aboard as well as explain, answer questions, and
give directions for using the systems on the vessel.
From the Surveyor's Notebook