They're good reels, but I wouldn't buy them specifically for sharking. Buy a pair of 50's, like a pair of old straight 50 internationals, or 50 tlds, both bulletproof reels. Loaded with hollow spectra those reels can handle any shark you might encounter in the NE and more.
P.S. If you do decide to buy 30s, definitely get at least 60# spectra on them.