An underwater Bluetooth speaker may seem like a neat trick for a pool party. Theoretically your friends could all dive in and, while under the surface, listen to your latest musical discoveries. After all sound travels better underwater, ask any blue whale. Maybe this is what JBL means by immersive sound.

The company has supplied pictures of their various waterproof speakers unarguably underwater and it promotes them as built to IPX7 standard, in which IP stands for ingress protection. These standards classify the rate of protection against intrusion from such nasties as dust and water, and IPX7 indicates the device in question can be immersed in water to a depth of one metre for up to 30 minutes without damage. Knowing this is possible you may now envisage tying the speaker to a brick and chucking it in the pool to impress all your aquatically-inclined mates.

Alas, it is not to be. While the speaker may be operational underwater, with all its electronics nicely protected and ready to roll, unfortunately Bluetooth will not be; Bluetooth does not transmit through water. Nor can you hardwire the speaker because the inputs are sealed under a tight waterproof cover and the moment they’re exposed you’ll get nothing but a soggy calamity.

But on the positive side the Xtreme2, JBL’s biggest IPX7 speaker, will float despite its two-and-a-half kilograms. And waterproofing is handy if the sprinklers kick in unexpectedly, or if your much smaller, lighter and also IPX7-rated Go2 speaker ($49.95) is in the back pocket of your jeans when they go through the wash, or if the tide comes in to lap your stuff while you’re out scaring the sharks.