A20 with two anti siphon loops per tank

[JackTHX]

I want to add some bags to the rear lockers of my 2012 A20, so I went exploring in the lockers to see what I have to work with. Looks like there is no plug and play components installed for the rear lockers, however I did find that there are two anti siphon loops connected in series for each of the rear tanks. So the plumbing goes fill pump -> loop #1 -> loop #2 -> tank fill. There's about 4' of hose connecting the two loops together.

This is the first I've ever seen or heard of connecting the loops in series. I'm left wondering, is there improved anti siphon performance with this configuration and this was done intentionally? Or is it possible that at the factory they started to add components for plug and play, then realized that this particular boat was ordered without it? Any other ideas?

I'd like to replumb this configuration to use one loop for the hard tank, and the second loop for the bag in the locker:

Does this setup gain me anything, or am I better off keeping the two loops in series and placing the wye after loop #2?

Cheers

[vanamp]

I had a 2012 A22 that had the second anti-siphon valve mounted there but nothing connected to it.