Lifting out a boat for a survey?

[Tryweryn]

Hi the continuing saga of a Moody 30 purchase.
Put an offer in for a boat. Got told today he will discuss it with the owner and the boat has gone in the water today. Is this normal when people are selling as besides £300+ to lift the boat for the survey, can you actually take hull moisture readings of a boat that literally just came out of the water? As they say they will lift it out at dinnertime and then put it back after the survey?

 

[AIDY]

I thought not. but when we sold our moody last april... she was lifted at sealift Gosport for a 1 hour slot and had various moisture reading and hull prop inspection with a surveyor . I they quickly antifouled the hull before she went back in. I was a bit worried about it but was told its quite normal.

 

[Tryweryn]

It is common for surveyors to take moisture readings on hulls during a brief (often just 1 hour or so) lift-out. Particularly with older boats, built using orthopthalic resins, high readings will almost always be obtained immediately after hauling out, but these will drop greatly if left ashore for a few days. This effect is less pronounced with isopthalic or vinylester resins - they are better at keeping out the water in the first place, but do not let it dry out again as easily.
Whilst epoxy coatings offer some protection to hulls from water absorption, the epoxies themselves can absorb water, and be slow to dry out - up to two weeks is sometimes quoted. For most pre-purchase yacht surveys, two weeks ashore before readings are taken may not be practical.
The International Institute of Marine Surveyors Code of Practice for marine surveyors recommends that "... ideally the vessel should have been out of water for at least 24 hours". It also sets out a complex form of statistical calculation to reduce randomness of readings and take into account local temperature and humidity when measurements are taken. I have yet to see a yacht survey report that actually used this calculation.

http://www.yachtsnet.co.uk/osmosis.htm

 

[Deleted member 36384]

The owner probably wants to sail while the boat is for sale and it is not unheard of for a test sail to be part of an offer as well. If it was me who was selling I would have offered to keep the boat on the hard for a limited time for a potential buyer to survey, if I was in the same situation. Then again, some yards book a crane and its launch on the day or not at all unless the owner hires a crane at their own cost, so he may have had little choice.

It is my experience that a moisture reading immediately after a lift has limited usefulness, not totally useless, but limited. My own yacht had a moisture survey carried out on a lunch time 'lift, hold and lower' and it was pouring down as well. I now understand, from reading literature on the subject, that this combination, wet hull and heavy rain, is pointless and that the results cannot provide any meaningful survey. I am happy to have that challenged as I am not experienced in these matters.

 

[Daydream believer]

Is it a bilge keeler
If so just beach it somewhere on a tide

 

[Tryweryn]

No a fin lol....i see why everyone wants a bilge now.

 

[jwilson]

http://www.yachtsnet.co.uk/osmosis.htm

Those are my words, but in practice surveyors are used to looking at boats lifted out over a lunch hour, and often in the rain. They can usually get a pretty good idea of the condition of the hull from a brief lift, though I think every one would agree that having a boat ashore for a couple of weeks is better. Problem with that is the buyer will be paying for not just for a lift and a hold in slings over yard lunch break, but for chocking off and shore storage, plus if midwinter engine winterising lest it freeze. We do get some sales where buyers request and pay for a period ashore before survey.

 

[Tryweryn]

Ive decided ill go for it as the specs seems so good so worth a survey.