vacuum break in head plumbing

[Artwerke]

I''m plumbing the head in my new 1970 38''Irwin,I can''t recall if the vacuum breaker goes between the Y valve & the seacock or between the head & the Y valve. Between the Y valve & the seacock seem to make more sense to keepfrom syphoning the whole ocean into my head. I saw a diagram on this somewhere,but can''t seem to find it.Any one know? Thanks in adv.
Art

[Gord-May]

If the head is installed below the waterline (as recommended), there are TWO vacuum breaks (vented loops);
First one 3/4" between the flushing pump & toilet bowl
Second 1 ˝" between the toilet waste discharge & “Y” valve (discharge seacock or holding tank).
All loops must extend at least 8" above heeled waterline. The waste loop should be as close as possible to the toilet, thus reducing the length of unflushed hose.

[Gord-May]

I’ve posted a crude Marine Head Plumbing Diagram, showing the Vented Loop locations etc, on the CruisersForum, at:
http://cruisersforum.com/photopost//editphoto.php?phoedit=1553

[Gord-May]

Sorry - the diagram is at:
http://cruisersforum.com/photopost//showphoto.php?photo=1553