I have a grand trunk ultralight hammock and a castaway gathered end hammock.
I am going to put a structural ridgeline on both of them but I don't know how long to make it, any tips or suggestions?
The rule of thumb is somewhere around 83% of the hammock length.
I lay my hammock, stretched out, on the floor and measure from knot to knot then multiply by ( .83 ) .
+1 on Flatline's suggestion. Use an adjustable ridge, so you can go a little longer or shorter, until you find the sweet spot. The 83% is just a starting point, some find it spot on, other a little longer/shorter to get comfortable.......RR
I'm a member of PETA!!!!
I run my adjustable SRL's on both my skeeter beeter (same as your UL with attached bugnet) and my castaway about 3" short of 83%, if that's any help.