“Insurers also want to know how much of a structure is going to be constructed at one time without final protection – i.e., how many metres of it will be completed before moving on to another phase of the works.”

An added complication is that many major port developments use caissons that are prefabricated elsewhere and towed to the site. There are obvious implications in terms of possible loss and calls on delay-in-start-up policies.

“Insurers have to consider the stability of these caissons, and will want to see contractors avoid the riskier times of year for transporting them,” says Ms Simpson.

There must also be a seamless interface between marine and non-marine insurance cover. For example, the towage of the caisson from pre-fabrication to construction site would naturally fall within the marine side – but as the caisson comes on-site and is manoeuvred into position, it must be very clear where the cut-off is from marine to construction policy, to ensure there are no caps in cover.

And insurers prefer more certainty, of course: “Tried and tested methods are always more welcome than innovative designs. Breakwaters that have been used before always provide a much higher level of comfort.”