Re: Pumps do not do what you think
Your best bet is to reduce the "head" that the pump has to push through, as much as possible, and have simple damage control equipment onboard that can quickly reduce a 1.5 inch hole to a trickle that the pumps can keep up with.
In addition to various wooden and foam plugs, I recommned Marine-Tex underwater putty and creating a 1'X1' heavy duty plastic or vinyl mat with grommet holes around the perimeter to act as a "belly band" for large holes.
Slap it on, tie it in place around the hull, and you can also put Marine Tex around the perimeter to seal things up.
This is all extreme, worst case of course. 99% of us will never need anything other than a wooden or foam plug.
S/V Old Shoes
1973 Pearson 30 #255