Pool end

[Accoes]

I'm trying to fill this end of a pool model so I can figure out the gallons of the pool. I lofted most of it but stumbling on how to get this end finished. Any ideas?

[lrm]

In the following I used the red and green splines for lofting profiles and the cyan line as a guide create a surface,

Here's the command sequence:

Command: LOFT
Current wire frame density:  ISOLINES=4, Closed profiles creation mode = Surface
Select cross sections in lofting order or [POint/Join multiple edges/MOde]: mo
Closed profiles creation mode [SOlid/SUrface] <Solid>: su
Select cross sections in lofting order or [POint/Join multiple edges/MOde]: 1 found   <-- red spline
Select cross sections in lofting order or [POint/Join multiple edges/MOde]: 1 found, 2 total  <-- green spline
Select cross sections in lofting order or [POint/Join multiple edges/MOde]:
 2 cross sections selected   <-- space
Enter an option [Guides/Path/Cross sections only/Settings] <Cross sections only>: g  
Select guide profiles or [Join multiple edges]:1 found  <-- cyan spline
Select guide profiles or [Join multiple edges]:
Command: