VThat is what they call salami tactics, every now and then a slice. I also wonder about these weather limits for an open unprotected bath tub, non enclosed, type of boat which probably has a marginal stability to boot.
It is remarkable that the Irish Ministry of Transport, after the Miss Majestic incident, immediately followed the NTSB recommandations and required as a safety measure the sponsons to be fitted on the Viking Splash Ducks to improve the stability and prevent ingress of water. Action which was not taken by the America authorities! The USCG is a darling for the operators.
Note that all passengers and crew have to wear life vests.
In fact the sponsons were probably not extremely necessary as the Dublin Ducks operate only in a very benign water system, the Grand Canal Harbour in Dublin and are not exposed to the same risks as on an open lake with quite a bit of fetch as in Branson. The irony is that such sponsons were very needed in Branson and essential for a safe navigation on that lake.