I was shopping around for headphones I could use in the water and found these were cheapest at Bicycle Superstore including delivery.
Only a few $ cheaper than club price at 99bikes but they don't have any stock near me.
Note - despite what it says on the site these aren't Bluetooth so there's no streaming.
I'd be curious just how good bone conduction headphones would work a) underwater and b) while swimming. Can't help feeling like the ambient noise from your head going in and out of the water, breathing, etc would be pretty loud