This advice is questionable. The last time I was in Russia, there was a legal requirement to leave your passport with the hotel for registration. It was returned a day or two later with a voucher that I had to show when departing.
The smart move is to do your own research before taking a personal vacation. Find out if, like Russia, you are required to turn over your passport. If not, then my preference is to carry my passport with me at all times. If something bad happens and I needed or wanted to go to the nearest US embassy or consulate, the passport would be necessary.
Leaving the passport in a stateroom and carrying a copy makes no sense to me. The whole reason to have a passport is so you can use it if you need it, and if it is on a ship out at sea you obviously can't use it.
For normal carry I use a belt that holds my passport and cash inside my belt. I also carry a passport wallet with a credit card and a limited amount of cash, which I use for normal transactions. I have never been robbed, but if somebody demanded my passport I could toss the passport wallet past them and take off running without surrendering my important documents.
I agree it is questionable. So in 2007 before our Med cruise, I wrote to the US State Department asking about this. I was told by the US State Department not to surrender our passports to hotel. Period. I was in Russia last summer and they do have very strict laws so maybe Russia is unique. I just have a real issue surrendering my passport to any non-government entity. Just curious, for the day or two that the hotel kept your passport, you went about your business in Russia with no passport or did you have to get it from the front desk whenever you left the hotel? I would politely say "You are more than welcome to make a photocopy of the passport but the US State Department advises me not to surrender my original passport to non-government official."
The OP was about taking your passport on
DCL excursions. I contend that the risk of it getting lost, damaged or stolen far outweighs the risk of 'needing it' becuase you miss the boat.
We were required to take our passport in Russia when we got off the boat....even on a DCL excursion.
Just for the record, I've taveled to Mexico, England, Scotland, France, Netherlands, Germany, Austria, Switzerland, Italy, Monaco, Vatican City, Spain, Liechtenstein, Morocco, South Korea, Canada, Japan, Bahamas, British West Indies, Norway, Sweden, Republic of the Marshall Islands, Russia, Denmark, Finland, Belize, Honduras, China and the United States of America and I have NEVER had to give my passport to a hotel.