In December Congress also expanded the Capital Construction Fund (CCF) program. The program is designed to encourage owners of U.S.-flag vessels to accumulate sufficient capital to acquire additional U.S.-flag vessels by offering tax incentives. The program works like a combination of a traditional IRA and Roth IRA. Like a regular IRA, an income tax deduction is available when funds are set aside and deposited into a CCF account and, like a withdrawal from a Roth IRA, withdrawals for approved vessel expenditures are tax free. Earning on a deposit in a CC account also grow tax free. Here is an article with more details.