That is because the people who live in the central to eastern part of Massachusetts do not pronounce the letter R correctly.
That is why you hear the joke about "pawk the caw in hawvawd yawd". :no
In English this sentence is pronounced "Park the car in Harvard Yard"
Given what I mentioned above you can see how "New England Lobster Divers" becomes "New England Lobstah Divahs".
Not pronouncing the letter "R" also seem prevalent to some degree in Rhode Island also.
People from western Massachusetts pronounce the letter R as do people in northern Connecticut.