I took a cruise because the weather is iffy there (as far as clear blue skies for that) and it was part of an astronomical group. I knew ahead of time I had an option to stay on the boat, which would chase a hole in the clouds if it came to that, or go ashore.
My group was lead by Fred Espenak, who maintains his Mr. Eclipse site and writes all of NASA's eclipse advisories. Also the late Ken Wilcox, who is sorely missed. As far as advice and info on how to deal with this, I don;t think I could have been in better company.
The day prior they had all sorts of weather data and predictions. No one quite knew what to do because most people were using high powered optics (scopes), and many were photographing the event.
If you stay on the ship, the ship will almost surely roll too much to get a decent shot, especially at longer focal lengths.
If you go ashore, one cloud could ruin the eclipse.
I went ashore, as well as Ken and Fred and most people in my group. The eclipse was around 2pm. I went out on deck to make my final decision just after breakfast; don't remember the time. Not sure I could have gotten a space; it looked worse than the image posted above.
We were totally clouded out until less than 10 minutes before totality, when the skies opened. It was truly a miracle. We were dead in water without hope (on dry land).
Here is the only advice I can give you on this very tough question...
A total eclipse is truly nature's greatest spectacle. No image I've ever seen can relate 10% of what you see. There is a reason these things supposedly stopped major battles in progress.
I think, given a choice, it is far more important to just witness it than to try to get what in most cases will be the same image everyone else gets. And that is true too of how you spend your time during totality. Don't forget to stop and smell the roses. Try to spend most of the time smelling the roses, and keep the gear as simple as possible in order to minimize the time and effort required. It is costing you $2,000 - $5,000 per minute to watch that thing
If you plan to stay on ship, practice a day or two ahead of time to see how you might deal with the roll. Don't assume the ship will be so close to port that it won't be an issue. If that is the case you might as well do it from land.