The sea trial is one of the most important elements of the entire survey process, with a lot of tests for us to complete within a short period of time, so time spent planning and briefing before the sea trial is always well spent. This article discusses goals, timings, priorities, pre-conditions, preparations to be made onboard, conduct of the sea trial and post sea trial reporting.
Sea trial goal
The goal of the sea trial as part of a pre purchase or condition survey is to establish performance of the yacht and key systems onboard under operational conditions. We are clearly not trying to replicate the performance achieved in the yacht’s original pre-delivery Sea Acceptance Trials (SATs) as yacht isn’t in the same condition that it would have been in just prior to acceptance; she’ll be older, probably heavier (carrying stores, spares and Owner’s effects that wouldn’t have been onboard at the time, making her heavier, and with some of those items likely being fragile. The yacht may also have a busy programme planned, which no one wants to interrupt due to machinery damage, so we need to be careful to avoid any risk of damage. In this respect, we see our task as pressing the yacht to the edges of the usual operational performance envelope, which is when problems tend to manifest themselves, without going too far. We achieve this by agreeing in advance the key parameters within which the sea trial will be held, as discussed below.
Sea trial planning
In the early stages of survey planning, we find that there are a number of common questions from both the buyer’s and seller’s team.
Clearly a key discussion will be how long will be allowed for the sea trial, as this will need to be negotiated as part of the sale and purchase agreement. Our recommendation is usually for 4 hours from breakwater outbound to breakwater inbound (ie ensuring that no time is lost during departure or berthing operations) if no noise and vibration trial is required. Where a noise and vibration trial is required, we recommend an additional 4 hours in order to accommodate their tests, ie 8 hours from breakwater outbound to breakwater inbound. If berthing arrangements make it impossible to open shell doors or to launch tenders whilst alongside or stern to the berth, then allowance should be made for up to 2 hours at anchor whilst these tests can be performed. The reality is that the sea trial will often be a long day.
Another question that comes up from time to time is whether it’s ok to combine with the buyer’s sea trial with the technical sea trial. We would encourage the buyer’s team to keep both trials separate, as their requirements are so different: whilst we are looking to test the yacht in every way possible (think turning circles and zig zag trials with commensurate angles of heel) the selling team will want to give the buyer a nice day out with a smooth ride. We also find that crew have their attention elsewhere whilst the buyer is onboard. Aside from these two points, in practical terms, the buyer may want to be confident that he actually enjoys the yacht before committing a considerable investment in the survey and haulout, so completing the buyer’s sea trial ahead of the technical sea trial gives the buyer that confidence. Whilst keeping the buyer’s sea trial and the survey technical sea trial separate is optimal, nevertheless, there have been and will be occasions when this isn’t possible. I’d also add that we’ve had some great interactions with buyers when the two have been combined, so perhaps there are plusses and minuses.
Specialist involvement
Another key discussion will be the extent to which we involve other technical specialists for the main engine, electrical and noise & vibration elements of the sea trial. Our advice would be that it is always beneficial to have specialists onboard for the main engines and electrical systems. On a diesel electric yacht, the latter is essential. For a large sailing yacht, the attendance of a rig & rigging specialist is also essential. In each instance, we can incorporate their work within our normal 4 hour sea trial without any issues.
Whether or not to engage a noise & vibration specialist is a more nuanced decision (for a deeper discussion on the use of specialists see our recent article here). When a noise & vibration specialist is involved, we would need additional time for the sea trial (as discussed above) as their tests require extended periods of steady state running during which we cannot be carrying out other sea trial evolutions.
Sea trial issues to consider
Once the survey planning has started, a lot of items need to be agreed prior to commencement of the sea trial. These will include:
- Duration of sea trial: will have been discussed as above and written into the S&P agreement, so we have to work within the agreed time allowed.
- Duration of endurance trial: specifically, this relates to the time during which we will need to run the engines at full throttle. Our standard ask is for 1 hour. This allows time for all engine parameters to stabilise (cylinder head temperatures, exhaust manifold etc). We sometimes get push back on running at full power, to which our answer is that it’s a diesel engine and that’s what they’re built to do, so we do insist.
- Stability/loading: in our briefing letter we request that the yacht is presented with not less than 50% liquids. This is to avoid repeating situations in which we have had problems with excessive heel angles under only modest rudder angles in very tender yachts that have been presented for sea trial with minimal liquids, or even worse, having to curtail an endurance trial due to lack of fuel. This isn’t acceptable. Whilst we appreciate that sellers may wish to minimise expenditure, having sufficient fuel bunkered is essential.
- Sea trial area: our key parameter here is to have a sea trial area free of heavy traffic, outside of VTS control, without navigational hazards and with sufficient water depth, with a minimum of 8 times the draft of the yacht, but in reality, greater than 50 metres.
- Tests to be performed: prior to the survey, we share our seal trial protocol with the buyer’s team. Tests will include a range of tests for main propulsion systems, steering gear, stabilisers, thrusters, navigation equipment and communications equipment, anchoring and mooring systems and, if not already tested whilst alongside, shell doors and tender launching and recovery systems.
- Operational limits: prior to commencement of the sea trial, we will discuss and agree with the Captain maximum acceptable values for key parameters such as momentary and sustained heel angles, engine load, wind speed and sea state.
- Safety: prior to commencement of the sea trial, we will also discuss and agree with the Captain the process by which tests are requested by us (which will always be initiated through the Captain or OOW on the bridge) and, if necessary, terminated. We will also ensure that procedures for carrying out any potentially hazardous tests, such access to switchboards or distribution panels without touch panels in place to allow for IR thermography, are agreed.
The list above isn’t exhaustive, and of course every yacht and sea trial will be different, but this gives a sense of the sort of issues that we will need to consider for each sea trial.
Pre-conditions for a viable sea trial
Whereas the SATs require conditions that are as favourable as possible with minimal wind and sea state so as to maximise the likelihood of meeting contractual acceptance criteria, for a sea trial as part of a pre purchase or condition survey, we are happier to work within real reasonable conditions, so long as the weather and sea state don’t compromise safety or performance. In reality, we would usually aim for wind stength of up to Beaufort Force 4 and a sea state maximum of 3 on the Douglas scale for motor yachts. As noted above, stability and loading is key, and we will change these parameters if we are presented with a relatively tender yacht that is lightly loaded. For a large sailing yacht, of course the parameters change and depending on whether or not the sea trial area is sheltered, up to Beaufort Force 6 would be acceptable. Of course, this is always subject to discussion and agreement with the Captain.
Preparations prior to departure
On the day of the sea trial itself, various preparations will need to be made: tanks will need to be sounded and contents recorded, drafts will need to be checked, ensuring that the yacht is on an even keel and within allowed trim limits, seawater temp and salinity will need to be recorded, and of course there will need to be a briefing for all involved. Our team will be onboard early to witness these checks and also to witness start up and pre departure checks. If the main engine technicians are onboard, they will need to connect up their diagnostic laptops and other specialists will need to carry out their own preparations.
Conduct of the sea trial on the day
Whilst there’s no hard and fast rule, we generally lead off with thruster trials whilst in sheltered waters, followed by engine trials, going through the RPM increments to end up at full power for speed trials and endurance trials, before slowing down to agreed cruise RPM for manoeuvring trials. If the noise & vibration specialists are onboard, we’d then provide time for them to carry out their measurements. After this, we’d ask the Captain to find a suitable spot to carry out anchoring trials, during which we’d pause to test shell doors and to launch, test and recover tenders (if this wasn’t already done in port). And then it’s back to port.
Post arrival checks
Once we’re back alongside, we’ll witness systems shutdowns and passerelle deployment. Once everything is settled, we’ll re-check tank levels and draft measurements. After a quick debrief, we’ll usually have the team disembark by 1800 after what will have been a long day for everyone.
Reporting and analysis
Once the survey team are ashore, we’ll immediately get to work compiling sea trial data, debriefing the technical specialists and compiling our preliminary report on the sea trial, which will be with the buyer’s team within 24 hours of completing the sea trial.
Specialist reports on the main engines, electrical systems and noise & vibration will inevitably take longer to arrive, but by debriefing them verbally at the end of the sea trial we are usually able to give the buyer’s team a good understanding of how the sea trial went and of any issues that may have arisen.
Conclusion
The sea trial takes a lot of planning and coordination to make it run well and to maximise the value obtained. For us, the sea trial is often the most interesting part of the survey process, working with the crew and our technical specialists to pack a lot into a relatively short time at sea. We always feel that there’s a collective sigh of relief once we’re back alongside. This is understandable. The sea trial is a critical part of the survey; successfully completing the sea trial is a significant milestone in the survey process and therefore in the overall transaction.
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