Oscar,
Do you mean the overboard discharge valve? (the BIG Sea Cock) if so, do NOT drive the boat with it open! That is a big no no, Federal Crime I do beleive...
The "Raw water intake" marked as "Toilet Water" is the valve I am speaking of. It's a much smaller seacock and feeds the toilet with raw sea water. The big sea cock (1 3/4") is the discharge valve and MUST be locked or physically secured to prevent accidental opening. Opening a black water discharge valve on US waterways is illegal unless you are more than 3-5 miles off shore in the atlantic or pacific ocean. It's illegal to dump black water anywhere in the great lakes or any other inland lake system.
Just want to make sure we are on the same page here, I don't want to see anyone get in trouble with the coasties, the feds or the local boys.
oscar wrote:
on my 258 it comes off in the same way.
Brett referring to your post of the discharge valve for black water, yesterday I made a trial: I took the black water discharge valve (into the engine compartment) opened while boating - at any speed, all the day.
I'm still here...

...the 258 didn't sink. Clearly before leaving the marina and the boat unattended for the full week I closed the valve. (unassembling the sun bed, removing the carpet, opening the compartment, entering the compartment, getting dirty, closing the compartment, .........

)
hi
Oscar