When I run my engine on the hard
I do the following:
1) Cut the female end of a garden hose leaving about 1 foot of hose
2) Buy a threaded garden hose shutoff
3) Run Full garden hose from spigot/hose bib to boat
(This is the supply line)
4) install threaded shutoff onto the male end of the supply line hose.
5) Install the cut-off hose onto the shutoff
6) close the sea cock
7) open the lid to the sea strainer
8) Close the shutoff on the supply hose
10) turn on the water
supply (bleed the air from the supply hose)
11) Fill the sea strainer with water
12) Have someone start the engine
13) Right when the engine starts drawing down water from the sea strainer turn on the shutoff.
At this point, you will need to manually tweak the water flow using the inline shutoff. It's easy to see whether you are overfilling, or under-filling the sea strainer. You will find a balance where the fill rate equals the draw rate.
NOTE: The 1 foot length of hose is to prevent water spraying everywhere when the inline shutoff on the supply line is half closed. without the hose extension, this makes for a very wet process. With the one foot section of hose, there is no spray, and the water stream is controllable.