WASC Recipe with Rum?

I’m baking a rum cake tonight using the WASC recipe. Do I substitute the 1 cup of water for 1 cup of rum or should I do half water, half rum?

And I’m using the Wray and Nephew White Rum. I made this recipe before with Bacardi rum but I cant remember how much I used. But the Wray and Nephew rum is much stronger so I didnt want to over power the cake.

TIA!