On pump noise/vibration... No doubt certain species are more sensitive to noise... Kayakers versus boaters on WSB counts is a strong testament.
But despite reading about it a lot on boards (people suggesting to turn off the pump when after WSB and what not), I'm not convinced that the constant buzzing of a bait-tank pump makes any difference.
This picture was taken a couple of years ago on our Baja trip... The school of 6-7 40+ lbs WSB strolled right under our kayaks to check us out. They were only 2-3 ft under our yaks, turning on their side to give us a look. At the time, I had an external pump that was pretty noisy. They didn't seem to care.
