Dave Hill

Thank you for your replies, I feel reassured once more.

Hi dmr Thanks for the reply. Your comment about the Morso Squirrel is interesting, as our survey showed that it was cracked & needs replacing. If you were to have a new one installed, what would be your preference? PS: Sorry if my question is misplaced & off topic (I can re-post in the appropriate section if required)

As a complete newby to this group I feel somewhat humbled by the expertise demonstrated in the replies. We are currently in the process of buying our first narrowboat & one of my concerns is that she is insulated with either polyurethane or polystyrene sheets. This is a 2005 Aqualine vessel which seems fairly well thought of. The type of insulation is one of my greatest worries, as I would imagine that the air gap between the polystyrene sheets & the cold steel wall of the hull, would be a likely cause of condensation on the cold surface. Clearly those vessels with a spray foam insulation, will not be susceptible to the same concern, as the air gap should (in theory at least) be non existent.