Modification of Boom Box :-)

[rbk]

Most charge via USB cable, just pick up a dc to USB charger available at almost every gas station around. Usually for $2-3 with dual USB outputs. I agree though, unless it’s waterproof that things gonna last about 10 min. You could also hook up a small solar cell and trickle charge as you go. Not sure why time is a serious issue, are you doing major multi day cruises? Or just day sails? Most rechargeable speakers last a good 8-10 hours for the cheap ones, good ones will go a full 24+ hours.