Reward for lost Kraken!
Join Date: Apr 2006
Thanked 132 Times in 129 Posts
Rep Power: 11
If you leave them ON the dock, then how do you tie up when you return? You can't, until after someone jumps on the dock, or someone on the dock throws you a line.
Where if you take the lines with you, you can always throw a line around a bollard or horn cleat and tie the boat to the dock, at least initially, without ever getting off the boat.
(Folks who run jump to the dock usually wind up falling on something at some point.)