My neighbor just bought these wearable speakers on Amazon for about $75. They're for around the neck, they have speakers and it's like the music is all around your head. It's not loud if you're not wearing it but it can be heard. It's built in little speakers and you put it on, it's like your all head is surrouded with music. I asked why didn't you get ear plugs or something and he said those have been proven to be bad for your hearing.
He's fishing out in a kayak every week and said this is perfect, because there's not a separate radio and IPOD or anything to get lost or wet. He plugs in a micro SD card of recorded music. I looked on Amazon and there many, many versions, some very cheap and some expensive.