Catamaran Hydrodynamic load?

Hello all,
Now I am designing 11,5 m Aluminum Catamaran with maximum speed 10 knots (electric motor propulsion)
I am using BV Rules for the Classification and the Certification of Yachts.

On this rule, I have some question about the hydrodynamic load (sea pressure & impact pressure on side shell) that will be affected to scantling of plate or stiffener thickness and dimension.

the load will be on internal side shell of the hull. in this section, the rule stated that I must calculate the minimum "Ps" for sea pressure load and impact pressure on internal side shell.
"Note: I exclude bottom slamming from the calculation because it is for high speed yacht. "

so, I got two different Ps: Ps=from sea pressure on internal side shell & Ps=from impact pressure on internal side shell.
when I calculate using Ps from sea pressure I got thick around 6mm, Ps from impact pressure I got thick around 11 mm. all the plate have similar frame space 0,5m for longitudinal and transversal stiffener.
my question is, which thickness that I will use to determine the internal side hull thickness for this case (6mm or 11mm)?
any suggestion for this?

thanks

 

No doubt 11 mm but try to reduce to the maximum the area of the shell that should be of that thickness.
By the way, you should use the latest version of the BV Rules for yachts.

 

Dear tansl, Thank you for your answer.

Omg, Thanks, I did not recognize that my rule is outdated