The US Coast Guard Marine Safety Center published an update to its technical note “Marine Safety Center Review of Rigid Hull Inflatable Vessels.” The document provides an alternative design standard equivalent to certain regulatory requirements found in 46 CFR Subchapters T and S for rigid hull inflatable and rigid hull foam collar small passenger vessels (RHIs).
The alternative design standard presented in the technical note provides consideration of the unique stability and structural characteristics of RHIs. These guidelines do not preclude the Officer in Charge, Marine Inspection (OCMI) from approving RHI structures and stability or applying alternative requirements or restrictions.
The major changes include adjustment of minimum collar material properties and clarification of acceptable drainage criteria and stability requirements.
This note applies to rigid hull foam collar small passenger vessels (RHIs) that:
– are constructed of a rigid hull;
– are less than 65 feet in length;
– carry 49 or fewer passengers in domestic service on any route;
– have collar volume of at least 60 percent of the full-load displaced volume; and
– have collars constructed with air-filled chambers or buoyant foam.