Do Magnets Work under Water?
Magnets work great underwater. You can even get special magnets, called retrieving magnets, to pick up objects containing iron that have fallen into lakes or wells. This can be a lifesaver if your keys fall into a tank of sharks or alligators.
It's also pretty easy to test if magnets work underwater Ė just hold two magnets underwater and see if they attract. If you have magnets made of iron you'll want to dry them off otherwise they'll rust. But youíll see that they attract just like on dry land. Now testing magnets in space requires a bit more equipment.
It's not all that surprising that magnets work underwater. Light and electricity don't seem to have much trouble passing through water.
Something odd about water ...
It doesn't seem like it would be magnetic but it turns out water, and all matter, can exhibit magnetic properties if you put them in a big enough magnetic field.
Water is slightly repelled by a very strong magnet. If you have a neodymium magnet you can test this out yourself. The folks over at NurdRage put together a video showing you how to demonstrate this. Skip to 1:15 to see. Note: they do speed up the camera since the effect isnít very strong.
Now, what would happen if you froze a magnet in water?