Jump on in the water is if anything a bit warm now days (Global Warming don't you know)
Some converters do make a lot of NOISE, as do Some LED lights.. and the "Ballast" (really an inverter) used on 12 volt Florescent lamps...
That last one used to bother me... However the ballast finally balled on me so I replaced the old yellowish Florescents with some nice bright WHITE LED's and without a dimmer.. NO NOISE as they were well designed and made. Less amps drawn too..