Well yes the boat though 60 feet long is only 6' 10" wide, this enables her to pass through narrow locks which are a nominal 7' 2". And that means in fact it is unsuitable foe the sea.
We can cross the Wash as quite a few NBs do it's a long trip and means a spell drying out but it is a quick way to get from the Cambridgeshire Fens to the port of Boston in Lincolnshire. To make a trip such as this foes mean waiting for the right weather
window there have been NBs that have crossed the English Channel
and one looney who did this took his boat the length of France
to the Med.
The same guy had his NB shipped to the States and travelled down the Atlantic Intercoastal Waterway from Virginia to the Gulf of Mexico
Check out his book...Narrow Dog to Indian River.The narrow dog is in fact his dog, a whippet a very skinny breed. Like a small greyhound
There are many people living on boats such as ours, in fact the canals in and around London are heaving with boats because rents for property in London are way, way above the average Joe's income
so they take to the water
as a cheaper alternative.