A company is looking to build wind turbines on an island, that same island is frozen or partially frozen three~four months of the year. I'm thinking that an operator with a large airboat might make a buck or two.
I presume the owner/operator is going to need a USCG licenses, insurance, and USGC inspection to keep the lawyers happy.
What else?

My suggestion would be to contact Dan Longman at Charter Lakes Insurance to determine what the underwriting standards will be to insure a commercial airboat in those circumstances. USCG will require - at the very least - an OUPV Merchant Mariner's license - if you transport 6 or fewer pasengers on inshore / nearshore waters while accepting any valuable consideration in return. Any more than 6 passengers will require a Master Mariner license. USCG will have Inspected Vessel standards if you wish to maintain the US flag while operating any Inspected Vessel for commercial purposes. I feel certain several major airboat manufacturers have experience with USCG Inspected Vessel status - best bet might be to contact them for their ideas on required construction standards.