The north shore is a must for romance.
Little beaches or grand ones are ideal for taking along the picnic basket or Bento box and towels. Kaena Point State Park has some lovely spots, as does Waimea Bay. Just off the Kamehameha Highway near Turtle Bay Resort is Kawela Beach, a pristine spot not everyone manages to get to. Many people opt for romance in the heart of the Waikiki Beach zone, too, or up by Diamond Head. Punaluu is nice, especially if you take the time to visit nearby Sacred Falls State Park. Grab or rent your snorkels and fins for a pleasurable time at Hanauma Bay, one of the world's most stunning coral reefs where you can see many tropical fish.
Hire a paniolo -- Hawaiian for cowboy -- and venture out by horseback through beautiful dense jungles or trails with views.
Kualoa Ranch in Kaaawa is a popular tourist attraction 45 minutes from Waikiki. On the opposite side of the island near Waimea, the Happy Trails wranglers will guide you through various settings with spectacular vistas. On the south shore, Koko Crater Equestrian Center also offers rides, through the crater itself and through the Botanical Gardens. Turtle Bay Resort, Gunstock Ranch and Kahuku-Kai Horse Ranch are other options. Make sure you take your camera.
Dine and Dance
Most of the major hotels around the island, especially in Waikiki, have good restaurants for dining.
Check the local listings for your favorite food choices and find a candlelit table for two. Try La Mer for French dining at the Colony Surf on Kealakekua Avenue or Sarento's for Italian at the Top of the I on Ala Moana Boulevard. Listen to live island music at the Hau Tree Lanai on the beach. Stroll the beach in the moonlight after your meal, or check out some of the clubs for your favorite kind of dance music. Check out the fancy Zanzabar at the Waikiki Trade Center or the Player's Club. For a more casual experience, dance together at the Pipeline Cafe near the Ward Warehouse.
On the Water
Get down to the docks to join others for a sunset sailing trip or better yet, go for the stargazing cruise.
You'll likely encounter dolphins as well as beautiful skies. If you prefer to head out by day, many different types of boating excursions are available. Try sunset dinner cruises, outings on smaller vessels, or if your budget allows, go on board the big Star of Honolulu cruise ship for a five-star exotic dinner followed by a night of jazz.