If you can change your location from "some where on the water" to the town you live in someone may know of a place near you that has it.
Red Cedar seems easy to find on the north shore, most lumber yards carry it. I've recently found Mahogany ballusters at a place in Salem that I've been using and they work well.
Yankee Lumber on rte 1 in Rowley has a good selection of different woods but they are a bit pricey and I'm a bit Cheap (did I say cheap....I meant thrifty
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