You can put heat shrink tubing in the ends and leave it 1/4’ long then heat and pinch it flat if you’re bored. Put tubing on before you cut bungee for the last time because it may flare out after cutting. I usually cut with really sharp knife of razor blade. The melt end slightly with a lighter and twist with wet fingers and the yell ouch.
Soon as you cut bungee it frays 
like in two seconds. Krazy glue and then cut it would work too.
From the replies, I’m thinking mine may be too loose. Time to re-knot.
You don’t need slack in your deck lines; slack lines make a boat harder to control during rescues. What you need to do is elevate the lines off the deck, so it’s easy to grab them even if they’re tight. The method I use is to slide 3/4" wooden beads on the deck lines. You can buy them for a few bucks a bag at any craft store. You’ll need to enlarge the holes in them slightly t fit your deck line, but they’re pre-drilled so it’s not difficult to do.
In this pic of my Anas Acuta, you can see the beads installed all the way around the boat on the perimeter lines, but they also help to get the paddle under the line near the compass.
You can also skip a deck fitting, if you have 3 or 4 fittings near the cockpit for bungees, so that the length of perimeter line is longer, making it easier to get your fingers under and hold onto.
