Size interpretation needed

[Orion27]

https://www.yanmar.com/marine/wp-content/uploads/2020/05/0AYMM-EN0028_2019.12.pdf

on pages 88-89 am I reading this correctly that I need a water hose with a .67 inner diameter for sea water pump intake?

 

[makomark]

for #19 & #24, I'd agree with your math...practically, I'd start with a 5/8" ID hose and go from there...