Lindblad Cruises is now offering free round-trip air from Miami for children ages 18 and under on select August sailings of the 96-passenger National Geographic Endeavor. This 10 day trip (with a seven night cruise) visits seven different islands and will provide your family with an abundance of wildlife viewing along with kayaking, snorkeling, Zodiac cruising and hiking. The ship also offers a glass bottom boat, expedition leader and four naturalists (including a Lindblad-National Geographic certified photo instructor, an undersea specialist and a wellness specialist) on board each sailing. Add-ons to Machu Picchu or the Upper Amazon River are also available.  Lindblad believes sharing an expedition with your kids or grandkids is a life-enhancing experience. So take $500 off for each child under the age of 18.