Err. I don't think the addition of a plant that may grow to 250 feet would be a suitable choice. Stick with the smaller pines closer to the shoreline, the wind will tend to keep them low.
As conditions in Boston would be closest to those in NZ:
-Metrosideros excelsa
-Yeogi (Populus alba x glandulosa)
-Juniperus conferta 'Emerald Sea'
Tee hee, Mr.S. I was just offering a variety. Besides, I don't think the Sitka Spruce reaches 250' for about 50 years. If somebody did want a nice big tree, though, it would be a good one. I'm from the Puget Sound area of the Pacific NW and here, we love to have big trees close to the water. They look good. You get your shoreline, then the trees, with a good lawn and some red geraniums... you're set and don't have to think about it again!
To my mind though, a row of Shore Pine, Pinus Contorta, would probably be a better choice.
