Are my Cocos Expedition costs tax-deductible?
Each country has a different set of tax rulings. 
USA: In the United States, Turtle Island Restoration Network is a public charity described under Section 501(c)(3) of the Internal Revenue Code. It is not a private foundation, as it is an organization described in Section 509(a)(1) and 170(b)(1)(A)(VI) of the Internal Revenue Code. In general, contributions of cash, securities and property donated by US citizens to support scientific research expeditions sponsored by Turtle Island Institute are tax-deductible. Note: Contributions of cash or securities to a charitable organization are tax deductible only upon completion of giving. As such your payment(s) toward a Turtle Island expedition may be tax deductible only after you have participated on the expedition. Under certain circumstances, volunteers may deduct reasonable out-of-pocket expenses associated with their participation in a Turtle Island expedition including some expenses for transportation to and from the research site. AS WITH ALL TAX MATTERS, PLEASE CONSULT YOUR PERSONAL TAX ADVISOR ON ALL ISSUES CONCERNING TAX DEDUCTIBILITY.