Yep you read it right YELLOW DUCKS.
For fun and to keep my niece and nephew busy I got them too making Solar Powered Yellow Rubber Ducks.
All you need is few tools a soldering iron solder a large yellow duck, I got theses from Smythe the Toy shop about £4.00 with some baby ducks, they escaped.
Some cheap and nasty Solar Lights I got 4 for £1 and a Pound Saver Shop.
A drinking straw and a plastic spray tube of a WD40 can.
A lump or metal about 200grm.
Hot glue gun and sticks.
In version 1 I used a old cassette players 3V motor and a cheap AA 1.2V Nickel Hydride battery.
In version 2 I used again a old cassette playes 3V motor and a 10F 2.5V super cap from a old PC.
I am about to do version 3 which will be the best so far and will paste up how you can do it for your kids etc.
The above toy is version 2 see the Red PCB used as a prop.
This is version 1 note the plastic Blue prop from a toy a broken windmill.
This one only powered up in the dark as I use the original solar light PCB so in the morning it was in a new position on the London Docks.
Version 2 only worked when it was sunny and bright but it could splash a lot so it looked funny.
So now go build you own, my version 2 will be up soon as I get a new prop.