Replacing a through hull live well pump

[Upnorth1963]

I bought an older fishing boat and the Attwood live well (model 4240) that is no longer in production needs to be replaced. I plan on replacing it with an Attwood Tsunami 4643-7. Question - is a seacock required,or do the pumps prevent water from entering when not in operation? I haven't taken the boat out of the water and looked at the existing pump installation. Thanks for your comments.

 

[dingbat]

Question - is a seacock required,or do the pumps prevent water from entering when not in operation? I haven't taken the boat out of the water and looked at the existing pump installation. Thanks for your comments.

Seacock are used as a fail safe should something happen to the plumbing leading up to the pump, ie. thru hull cracks, fitting corrodes, hose rots out and breaks, etc.

If water comes in when the pump is off depends on the fitting outside the hull.

I use scoop type intakes on my pump which harnesses the tidal flow while anchored to pump water w/o using a pump. The downside is that I've floated a few lunches by not closing the seacock when using the bait well for dry storage for the day.