1. Seashells
Due to its unique east-west orientation (most barrier islands run along the coast) and gentle surf, Sanibel beaches are like a giant catcher's mitt for the multitude of beautiful seashells, large and small, in the Gulf of Mexico. From treasured miniatures to fighting conchs to the rare junonia, Sanibel offers treasures ... and often without any effort required. The beaches are chockful of seashells. 
Sanibel's beaches are strewn with seashells — Photo courtesy of Libby McMillan
2. Gentle Surf and Slope
Parents love, love, love the way the water stays shallow close to shore on Sanibel. You can literally wade out for hundreds of yards and not be in deep water. Thus, small tots have ample opportunity to get wet without getting overwhelmed by surf or nasty drop-offs. 
Sanibel beaches slope gently, even beneath the surf — Photo courtesy of LIbby McMillan
3. Warm Water
While winter temps can make even the Gulf a little nippy, it's certainly nothing compared to northern lakes and shores. Typically, however, summer Gulf temps are like a bathtub, and spring and fall are delightful. Kids love to splash and play in warm water and you can relax, because they won't be turning blue.
3. Dolphins and Wildlife
Nearly half of Sanibel is protected as wildlife habitat and the sea and shore are teeming with dolphin, shore birds, tortoises, funny racoons, tiny lizards, and more. Back bay waters hold the amazing manatee. There's a famous wildlife rehabilitation center which does educational tours. Kids laugh when they see Alligator Crossing signs and cars stopping to let birds walk across the road. [PHOTO_221286]
4. Family-Friendly Resorts
Sanibel is all about families and it's usually evident at check-in, particularly at some of the larger resorts. Look for properties which have children's programs when booking if you'd like some adult time to yourselves. Kid's menus are easy to find at many resort restaurants, and it's easy to find decor touches which tickle the kids. Many resorts of all sizes offer bicycles, so inquire. Best of all, Sanibel has a flip-flop dress code. Literally. Packing for your kids has never been so easy. Shorts, tees, sandals, swimsuit. You're done.
5. Bike paths
Seventeen miles of bike paths open the island to exploration on bike. Kids love the freedom they have and one of the main sounds you'll hear on the island is the ting-a-ling of a bicycle bell. [PHOTO_221287]
6. Sunshine
Southwest Florida has the best weather in the country during winter months, and the rest of the year it's sunny and inviting. If your gang likes to play outdoors, there's no better bet than Sanibel, no matter the month. 
Sanibel's beaches are nearly always sunny — Photo courtesy of jhetzel
7. Special Events
Sanibel is a great place for families to enjoy the 4th of July and Christmas. Festivities range from annual road rallies to fireworks shows to luminary night s and tree lightings. And if you'd like a new place for your kids to go trick-or-treating, local residents are receptive! No matter what holiday you choose to visit, it wil be unique and memorable. The island makes it so! 
Christmas Eve service on the beach — Photo courtesy of Lizard10979
8. It's Easy to Reach
Fort Myers, Florida (the nearest city on the mainland) is served by Southwest FLorida International (RSW). Yet both Tampa and Fort Lauderdale airports are only 2 hours away. And Miami is about the same. Low-cost carrier Allegiant flies into nearby Punta Gorda and also Clearwater. Orlando and Sanford are doable, too. If you're driving, Sanibel is mere minutes from I-75.
9. Affordable Rates
Sure, February hotel rates are expensive: much of the world is freezing. But two weeks after Easter, rates drop on Sanibel and deals can be had. If you want a REAL bargain, aim for August, September or October ... (but be aware that once in a blue moon, an impending storm can force an evacuation). My favorite months are May and November, when rates are down, there are no crowds and the weather is lovely. The first two weeks of December are another big bargain.
10. Dolphins
This one is so important, we're listing it twice !!! Kids love dolphins and Sanibel has loads of them! If you want an up-close and personal view, book the Dolphin Tour offered by Captiva Cruises on adjacent Captiva Island. After the boat gets out of the channel, take your crew down to the lower rear deck and be prepared for full breaches by adult dolphins .... RIGHT NEXT TO THE BOAT. It's the most fun your kids could ever have on a vacation. 
Dolphins are easily seen from boats and beaches — Photo courtesy of Libby McMillan