I get seasick a lot, so the Scopolamine patch was fantastic for me...... or so I thought. I used it on several dive trips, dives were great, I didn't notice any negative side effects.
After about a year of using it, I had at some point noticed that i couldn't read my computer well. I was using a very small wrist computer, so I figured that was just my eye sight getting worse. ( I wear contacts while diving). I bought a bigger computer, and all was good, until my next dive with the patch. I did some research. Many people experience blurred vision as a side effect, which is not a great one for diving.
The Scopolamine patch worked far better than any oral medication I have tried, but I suggest trying it a couple times in a safe environment before you go diving and see if you have any negative effects.