hypothetical question about a cruise ship?

Question

Ok, this is a really random hypothetical question. If you took a running jump off of the top deck of a cruise ship and survived, (e.g. didn’t die upon contact with the water, didn’t come back into the side of the ship on the way down) how far out in the water would you have to be from the cruise ship to have a reasonable chance of swimming to safety w/o getting pulled in by the suction of the cruise ship’s propellers? also, does anyone know the approximate diameter of the propeller of a cruise ship? (lol, besides just really big?)

Answer 1

I was in the Navy during the Viet Nam war and we had several shipmates that wanted out of the Navy (The draft was gong strong then, which is how most of us ended up in the Navy). We had a fellow jump over the side one day. He jumped from near mid ship of the Destroyer and was later picked up by a Helicopter. I was aboard at the time but did not witness the "leap". I do know that our screws were turning and large enough to stick out from under the ship requiring heavy "guards" welded to the sides near the stern. He would have been a lot lower to the water when he jumped than you would ( not a deep dive) and we were not going the usual 18 knts of a cruise ship. The ship was also smaller, about 300 ft or so. Bottom line, he survived uninjured.
About propellers pushing, not sucking. They do push, they push a lot of water that has to come from somewhere. That pushed away water would be comming from infront of the propeller. Kind of like a wind tunnel does with air. Last thought on this: Myself and three friends took an old 100ft Chesapeake Bay "Buy" boat to Florida back in1982. One of my most thrilling (and stupid) experiences was holding onto a line (using a snorkel to give me a little more time), and swinging under the boat about 20ft in front of the slow turning (about 4 knts.) 54 inch three bladed prop. We were off Palm Beach where the water is crystal clear and about 1000ft deep up close to the shore. Seeing the prop turn in that deep blue water was one of those awe inspiring life experiences.....So if you do make that Jump, don't forget to look for the prop., and remember you won't have a line in your hand so it could be the last thing you ever see.

Answer 2

What do you mean by "swim to safety"?

If you are worried about getting sucked in by the props, the distance you jump and clear could be enough. Props don't pull, they push, so there really is no "suction" before it. There is allot of turbulence after the props have churned up the water. I have passed by tugboats in the channel in a 40' sailboat and have been spun around by the wash.

Diameter of props vary but you could be safe estimating between 15 to 20 feet. pitch is about 30. Most are made of bronze and have 4 to 5 blades.

Answer 3

I have sat on the decks of several cruise ships and watched the water. The ships displace a large amount of water as they move along creating large wakes and an incredible amount of turbulance behind them. I do not beleive anyone jump far enough away to miss being tossed around in that soup. I beleive those stories of people falling off a moving ship and being picked up by another ship are urban legands.

Answer 4

If you jumped off the bow, the bow wake would push you out to a clear safe zone. The wheel is so far below the surface on a cruise ship, you would probably never get sucked in unless from your jump you get deep.

Answer 5

The prop is about 4 metres in diameter. 4 blades on most!

Answer 6

That is one of the most interesting questions I have seen in a while.

Sorry that I can't help answer it, but I'll be checking back to see what other folks have to say.

Thanks for posting something intriguing!

Answer 7

It all depends, on you'r body shape, temerature of the water.

Answer 8

Methinks you're planning to fake your death. EH?