Suppose your schedule changes and you miss a place where your mail was sent. Also, how careful will they be with the mail?

Are you talking long term or a few weeks cruise?

There are forwarding services that will open, scan and email the images to you.

I think the best solution is to get a trusted friend or relative to handle it. I did that for many years - my sister had my power of attorney and my checkbook to handle bills. I talked to her periodically from all over the world. When the internet and email became available things got easier.