weight -vs- drag

[Andy]

Hey all, I have a question/ argument that hopefully applies to this
group.
Any help would be greatly appreciated.

So the argument is as follows:
Two surfboard of equal dimensions (length and width, i.e. wetted
surface) yet differing weights (mass) when going down the face of a
wave (from displacement Froude's Law of Comparison “I think” to a
planning hull), the board that has the greater mass will accelerate
faster.

I may have backed myself in a corner as I argued the Galileo showed
~400years ago that this is not the case; they accelerate at equal
speeds (rate). My reasoning was the surface area remained the same
between the two boards, with the gravitational force being = between
the two along with the wetted area, the acceleration should also be
the same. Although herein lies my corner, we are talking about water
with a fairly large surface area (drag) not an easily rolling ball (a
la’ Galileo), nor a vacuum.

So let’s say a 10’ elliptical shaped board 24” at the widest point,
with one that weighs 10lb and another 20lbs (40, 80lb?) with the same
rider mass.

Wave height let’s say 30’

So which is correct?
And why?
If there is a difference, is it linear relationship between weight and
acceleration.

Thanks much,
Andy