Most folks give up on using the UR PRO filters almost immediately, certainly when they get an external strobe.
No one uses them, in any of the photo credits I have ever seen.
In clear bright tropical waters, you don't need any filter in the top 5-10 feet. From 10-30 feet, a filter might be useful, with no flash - just trying to shoot ambient.
But 99.9999999% of all shots, are done with no filter, and plenty of strobe, to put the colors back, down 30-130 feet...
This gives the nice bluish backgrounds, with the subject standing out more.
Don