By far the best way to see the stunning coastline near the beach town of Cala Gonone, on the east side of Sardinia, is by kayak. My husband and I hired a couple of kayaks for a day and paddled our way to some of the area's most secluded beaches, including the idyllic Cala Luna (setting to Madonna's film Swept Away), which is only accessible by boat. A fun and self suffiicient way to view sealife such as jellyfish and the cavernous caves along the coast, not to mention a great way to introduce some exercise to a beach holiday.
Kayaks are readily available from the promenade in Cala Gonone.
Google map: bit.ly/MzlwWF