Initial setting of strut height on a hydro

[Old School]

I will be soon mounting a flat bottom Speedmaster Sport 20 hydro strut to a medium size hydro and require some basic height setting information please to set the neutral point.

With the hull sitting level on the aft tip of the sponsons should the flat bottom of the strut rest on the surface or should the centreline of the prop be the setting point please?

[rol243]

Start with the strut sitting on the table plus have the underside of tub parallel with the table.

[Old School]

Many thanks