Wake shapes

[you da man]

the malibu is a 2000, 3 years older and is not much bigger than the Moomba, the beam is definately smaller, more freeboard, and maybe an inch or two longer.

That's the reason, it's more narrow with more freeboard AND a Malibu so it's heavier built. All this equals to that boat sitting deeper in the water which is displacement which equals wake.