I built a Hartley RORC 32' too long ago now and I would suggest that it is not really possible to determine if a Ferro boat is blue water
capable before purchase
There is no real history
as with some of the "mass" produced fibreglass boats.
The following assumes a reasonable level of experience with boats.
What you can do is go through the steps as already discussed in this forum. My understanding is that the process would work like this ( this really is only looking at the ferro part, the rest needs to be checked by other means)...
1) Generally check the boat, looking for cracks or rust marks.
2) Check that all deck
gear/rigging/etc. is through bolted with appropriate backing plates
3) Check that the boat sits properly to it's waterline.
4) Check that an appropriate impervious coating has been applied to the bilge
and the interior
of the boat so that bilge water
never comes into contact with bare cement. (Tar epoxy
on a penetrating epoxy
primer comes to mind.) My understanding is that oil
(esp. diesel) and sea water will destroy ferro cement.
4) Check that all equipment
on board operates "normally".
5) Take the boat for a test sail, preferably in about 15 knots of breeze with gusts to 23 knots. Particularly watch for tenderness or heavy weather helm
(insufficient ballast/top heavy).
6) If you still like the boat then look for a surveyor
with experience in ferro.
At this point it is probably a go or no go on the purchase
If you do buy the boat my opinion is that you need to slowly work your way through various operating conditions. I'm not suggesting looking for bad weather, rather that as the boat is used in benign conditions that there will be the occasional outlier that will give a good idea as it's capabilities. I would strongly suggest that buying
a boat and immediately doing blue water cruising is not a good idea. (And I don't think that this applies just to ferro boats.)