There are screws holding the valve to the boot. Use some soapy water and a spray bottle to see if it is just the valve or the boot or both. If it is the valve only the fix is way easy.
Just replace it. But try to get a stainless one. The nylon ones are subject to failure due to over tightening, which is a common gomer mistake when the boat doesn't hold air.
Your baffles are likely blown but that is a big fix. If the boot is bad then cut it out at the edge of the recess and glue a new one over it with an over size hypalon donut over the flange. use a bag of pea gravel or sand to clamp it till cured - it will provide even pressure over the whole area . Also, there are 4 SEPARATE chambers and valves in the boat for a reason...