Just curious if it will flood the engine bay? The front circulating pump...not the raw water pump. Thanks.

Ayuh,.... Sure,.... the leakage should be 'bout as much water as is in the block,.....

Is the engine fresh water cooled? With a heat exchanger? Then you'll only lose engine coolant, that flows in the engine block and part of the heat exchanger.

If raw water cooled, you'll have to close the water inlet shut-off valve right where it enters the hull.

If you don't have a shut-off valve, the water will only flow into the hull if the opening of the system is at or lower than the water line.

Always best to pull the boat for those repairs if you can.

Thanks. Yeah, just a normal raw water cooled engine...Bravo One 7.4MPI. No water shut off available.
The question came up in a discussion about keeping spare parts on a boat and what repairs could be done on the water in an emergency.

If your circulating pump block holes are above sea level, you’re good to do it in water. Almost all are.