The good weather part is the essential bit to understand. The English Channel or crossing to the Bahamas from Florida is about 40-50 miles. On a good day no big deal.
But in a blow, the GT27 shouldn't be out there.
. To change the Cp you have to change the hull form. Not something most folks would worry. The difference is not huge for different speeds in terms of efficiency. Few of us motor or sail at just 1 speed.Is there a function that I can enter SLR and get Cp?
Most of those areas are fine because the fetch is small. Barnegat and Raritan Bay and parts of the St. Lawrence can be much more exposed so you'd be restricted in how rough you'd want to take it those areas.the St. Lawrence seaway, Erie canal, Hudson River and South possibly to the the Chesapeake. This area includes open water of Lake Champlain, Lower Hudson River, Raritan Bay, Barnegat Bay, etc. for which it is not suitable to cruise in even moderate weather conditions.