I can understand the transverse (lift) force now

Considering phase 0 at all elements, the line has two nodes, guide + lim at one node and guide only at the other. Wave direction cosine is in Z.

Load case review: Wav1 only

Case #1:
The line is in vertical direction, lift force is now in X direction. Total lift force Fx from output can be checked by manual calculation = (0.5*D*rho*Cl*avgV^2)*element_length. But how to verify the sign +/- of Fx? I see the output is showing positive values.

Case #2:
The line is in horizontal X direction, submerged somewhere in the middle of water depth, the lift force now is in Y direction. I'm trying to verify Fy. My questions: Total Fy = total lift force + total inertia force? And how to verify the sign +/- of Fy?