I have a question on international maritime law, and I'd be grateful for
an answer from anyone who actually knows the answer.

I'm a sailor, and a life extension enthusiast. I'd like to sail to
Russia next year (Odessa, most likely) and purchase a supply of
Skulachev ions for my own personal use. While Skulachev ions are not
contraband, that is, they are not a controlled or prohibited substance,
they are also not approved yet anywhere outside Russia. With a
prescription from a US doctor, I could bring up to a 3 month supply back
to the USA with me, but a course of treatment is 6 months,
uninterrupted. So, I have thought that perhaps I could just take my time
sailing back to the USA, using the Skulachev ions as I go. So here's the
question:

If I am aboard a US flagged vessel at anchor, NOT dockside, in a
friendly foreign port, is it lawful for me to have an unapproved
medication for my own use on board my vessel? DO I have to declare if I
don't intend to bring them ashore? I've googled for "Legal status if US
ships at anchor in foreign ports" and got tons of stuff on totally
unrelated subjects, and nothing that remotely related to my question. I
am hoping someone here either knows the answer, or can tell me where to
look for it.

TIA!

Joshua

BTW, I'll be sailing back through the Mediterranean, and ports of call
will likely be in Greece, Turkey, Italy, France, and Spain.