As far as the tax instructor. I can see where she's coming from, but I kind of disagree. just because the IRS might disagree and disallow a deduction doesn't mean it isn't legitimate and something that you COULD choose to include.
That said, the charity that the OP mentioned is a "qualified" organization. Good, first criteria satisfied.
Next, you need to have documentation of your contribution. That could be a memo from the organization acknowleding your contribution. Certainly the gas receipts would be a given if you're going for fuel expense.
You don't get to deduct your time. I'd skip the idea of wear and tear or depreciation on the boat. But fuel I would most certainly do if you have the receipts. Heck, even if I didn't have the receipts per se, I'd keep a copy of my credit card statement and use that as backup should your deduction ever be questioned.
Remember, the only time you'd actually have to furnish said documentation is if you were actually audited. So really, if you have a legit contribution of your gas to this charity, then what you're really doing is weighing the value of that deduction vs the risk that it could increase your chances of an audit and in turn have the hassle factor. So if you're one that would just as soon avoid an audit, you can certainly not claim something that is likely to up your chances. For example, the "home office" deduction is a huge hot buttom that will increase the chances of an audit. Many who legitimately have a home office skip the deduction because they simply don't want to increase their audit risk.
Those are my thoughts. I'm NOT a tax specialist by any stretch, but I am a CPA and am happy to share my thoughts.
Here was an article that I thought was interesting on the topic:
https://ttlc.intuit.com/questions/18...s-can-i-deduct