Gary Warner wrote:
Question: Is this enough to keep junk like plastic bags from clogging my
water intake, or do I need something else?
It is cheap insurance and good practice to place a strainer between the
seacock and the raw water pump.
The strainers shown here by Groco are excellent for your application as
they allow visual inspection and are easily cleaned:
http://www.depcopump.com/catalog106/PAGE56.PDF
Rick