Combine water and salt in 5-quart casserole.
Cook, covered with lid, at HIGH 5 to 6 minutes, or until boiling.
Tilt dish; place lobster in dish, head first.
Cook, covered, at MEDIUM 14 to 16 minutes, or until shell turns red.
Let stand, covered, 2 minutes.
To test for doneness, slit tail section; lobster meat should be opaque.
If necessary, cook, covered, at MEDIUM, an additional 1 to 2 minutes.