Stepping on board a sailboat, you immediately feel connected to the ocean that it rides on, and the winds that make it go. Those sensations are accompanied by an emotional release, as life on land is left behind for a sun-filled horizon, and a boundless sea. Sailing Heals, which is based in Haverhill and recently opened a Salem office, was founded 8 years ago to provide cancer patients with this exhilarating experience.