Large flexible clear ball, twenty feet or so tall.
Lower half filled with water.
Motor boat in that water.
Reverse the motor boat, the water gets pushed to the front of the big flexible ball with a big wall of water in front of the boat, one side is heavier so it rolls forward.
The only reason this wouldn't work is if it didn't. When you're taking water away from the back of the boat to pile it up in the front, that side would "deflate" as well so I'm not sure if this would move forward or just sit there.
Another thing you could do is just have a big water tight hamster wheel looking affair with buckets on the inside. The boat just sprays water into the forward buckets making the front side heavier and rolling the whole thing forward.-- doctorremulac3, Aug 12 2017 Reminds me of a rather famous old discussion here... Roaming_20Goldfish_20Bowl [RayfordSteele, Aug 12 2017] USS Indianapolis found after 72 years http://www.bbc.co.u...-us-canada-40991326Coincidence [8th of 7, Aug 20 2017] //The only reason this wouldn't work is if it didn't. //
[marked-for-tagline]-- 2 fries shy of a happy meal, Aug 12 2017 cough... cough... goldfish bowl...-- RayfordSteele, Aug 12 2017 I foresee problems relating to the exhaust fumes from the engine.
cough... cough...
suffocate...-- Wrongfellow, Aug 12 2017 Doubleplusgood-- 21 Quest, Aug 13 2017 //a big water tight hamster
You mean, they aren't watertight? Seems a bit of handicap dontcherknow?-- not_morrison_rm, Aug 15 2017 // they aren't watertight? //
Sadly, no. No hamster has ever swum the English Channel, descended into the Marianas Trench, or won an Olympic medal in an aquatic event.
They are, however, very good for cleaning ink off dry-wipe whiteboards.-- 8th of 7, Aug 15 2017 Put your flexible, clear ball of water within another less- flexible ball of water. Attach the stern of the boat to the inner ball with a strong bungee cord.
Now, accelerate the boat. As the bow nears the wall the bungee begins to stretch, pulling the aft portion of the wall inwards and moving that water forward. The bow touches the wall, distending it and the temporary cavity created fills with the surge. The boat, water and both spheres slosh forward.
Maintaining this rhythm your boat should move over hill and dale, hopefully to the nearest pub.-- whatrock, Aug 15 2017 >No hamster has ever ... descended into the Marianas Trench...
Don't be too sure about that.-- AusCan531, Aug 15 2017 Have you ever seen a hamster wearing an "I went to the bottom of the Marianas Trench and all I got was this lousy T-shirt" T-shirt ?-- 8th of 7, Aug 16 2017 They'd have to 'ascend' to get the T-shirt. All they got was those lousy cement shoes.-- AusCan531, Aug 16 2017 Presumably the cement shoes are provided by hamster gangsters.-- 8th of 7, Aug 16 2017 //>No hamster has ever ... descended into the Marianas Trench..//
Not alive anyway.-- doctorremulac3, Aug 16 2017 // you could use a hamster as a guinea-pig //
Sure, if you were OK getting sued by guinea-pigs complaining about immigrant hamsters taking their jobs. Next, there'd be guinea-pigs rioting in the streets, other rodents would join in, pretty soon you'd have complete social breakdown, anarchy, looting, the collapse of civilization, and your world would be plunged into a new Dark Age, probably dominated by a Capybara elite.
Well done, [Ian]. Really, you need to think your ideas through more carefully - you have no idea how much damage you could do.-- 8th of 7, Aug 16 2017 Why not build a caterpillar boat?
First, imagine a giant tyre. Now stand it on its rim (ie, in the normal orientation for a tyre). Now fill it with water, up to the lowest point in the rim. Now put a boat in the water, and put a roller on the nose of the boat.
Boat thrusts forward, nose hits the inside of the tyre, pushes tyre, tyre rolls forward.
Yes yes, I know, physics. But still.-- MaxwellBuchanan, Aug 16 2017 Don't you think you'll need a rudder?-- piluso, Aug 16 2017 Not if the boat is wide enough, shirley ?-- 8th of 7, Aug 16 2017 Lower half filled with water. Motor boat in that water. You get in boat.
Farewell And Adieu You Fair Spanish Ladies...-- TheBamforth, Aug 18 2017 <Hooper>
"You were on the Indianapolis ?"
</Hooper>-- 8th of 7, Aug 18 2017 <suspicious>
What do you think this is, Westworld ... ?
</suspicious>-- 8th of 7, Aug 18 2017 <link>-- 8th of 7, Aug 20 2017 random, halfbakery