Just leave the lines in place and tie them on with a bowline. A bowline is quick to tie and pretty easy to untie. This has worked for many, many years. I would vote no to using a shackle.
"When in command, command." -- Admiral Nimitz
Difference between a power boater and a sailor out on the water: A power boater is going some place special, a sailor is already there.
s/v Zotz 1981 Pearson 365 Ketch Hull #375