How to Size up and Setup a Raft Perimeter Line

So, you have purchased a raft, it has all these unused d-rings on the outside of the boat, what are you supposed to do with them? 

There are multiple uses for the many d-ring surrounding your boat, Primarily they are used to attaching frames, seats, and platforms however, they are also ideal attachment points for complex rescues or securing gear and drybags with locking carabiners. For more adventurous paddle rafting or whitewater they can also used to attach a full perimeter line to.  A perimeter (or anecdotally known as a ‘chicken line’) line is a key safety feature that allows people to hold onto it for balance in rapids or, for people to utilize when re-entering a boat after either voluntarily or involuntarily exiting said boat!

Perimeter line questions we often receive are:

  1. What can I use for a perimeter line?
  2. how much rope do I need for my perimeter line?
  3. how do I setup a safe perimeter line?

For this post we are going to tackle all three questions in a good amount of detail.

WHAT CAN I USE FOR A RAFT PERIMETER LINE?

The 2 options we recommend are either:

5/8” Braided Polypropylene Rope: 

PROS:  Quite resistant to sun damage and rotting (when kept wet for extended periods), they are easy to hold and handle and easy to tie knots in. 

CONS:  They are dynamic so over time they will stretch and when re-entering a boat (especially if you don’t have knots tied in every d-ring) they will flex a lot, taking away some of its effectiveness when you are trying to clamber back in the boat

1” Tubular Webbing: 

PROS:  These are static (so no flex in the system), super high breaking strength, can be bright in colour so easy to see if you are in the water. Some may also argue that the webbing lies flatter to the boat, reducing the likelihood of a foot entrapment or getting caught up on a knife or other pfd accessory when climbing back in

CONS:  Much harder to hold onto than braided rope, a little susceptible to sun damage if out in strong UV for extended periods of time, harder to tie knots in when setting the boat up as well as untie when it comes time to adjust or replace

SUMMARY:  That is a brief rundown of our two favored options.  Neither is better than the other, personal preference or experience really dictates which one to choose.

HOW MUCH ROPE DO I NEED FOR MY RAFT PERIMETER LINE?

This depends on a couple of factors:

  • Raft length
  • Are you tying knots in each D-Ring?

The short answer is however, if you ARE TYING knots in each d ring then take the length of your raft and multiply it by 3 and add the width multiplied by 2, if you ARE NOT TYING knots in each d-ring, then multiply the length and width of the boat x 2 and add them together.  That will give you the approximate length of rope or webbing required

EXAMPLE:

NRS OTTER 13 Raft

  • No Knots in D-Rings: (13’ x 2)+(6’x2) = 38’
  • Knots in ALL D-Rings: (13’ x 3)=(6’x2) = 51’

Note:  tying knots in each d-ring can consume 2 - 3 feet of rope per d-ring.  So, bear this in mind and consider purchasing a little extra webbing or rope to ensure you have a bit extra. 

Handy tip:  Extra webbing or rope can be used as a quick access bow line once the boat is in use!

SUMMARY:  The 13 and 14’ rafts we typically deal with have 10 d-rings, so calculations are based on this.  If your boat has more d-rings and you are going to knot all of them you will need to up the amount of rope/webbing to buy.

HOW TO SETUP A RAFT PERIMETER LINE

There are many ways and opinions on how to do this and we can’t possibly cover all of them, so we are going to focus on how we go generally go about it.  That is tying knots in all d-rings.

We choose this method for safety and functionality reasons for our particular usage purposes (family multi day whitewater raft trips and gear boating on kayak support whitewater trips)

The SAFETY reasons we believe make a knot in every d-ring desirable is it leaves less potential for slack in the system which minimizes entrapment hazard (people or external river hazards)

The FUNCTIONAILITY piece is equally important, with slack in the rope there is little to no tension, so if you are trying to get back in a raft after falling out there is nothing to push/pull on.  This will likely render your efforts useless.  With knots in all d-rings you will have ample tension to give a better likelihood of getting back in the boat unassisted.

What you will need

THE PROCESS (this will be the same for webbing or rope)

  • Start by partly inflating the raft. About half pressure, so still looking soggy!  You need to have room for it to expand
  • Tie the line to the lead (front) D-ring. We personally use a re-threaded figure-8 (Click here for tutorial) or bowline (Click here for tutorial) for this starting knot
  • Take the line and run it to the first d-ring, have it in a pretty straight semi-taught line. Once you dial in the length, tie a clove hitch (you can use an overhand knot or other varieties if preferred) into the d-ring.
  • Now repeat this step on the next d-ring.
    • Now STOP what you are doing. Get your pump and fully (or close to) inflate the boat.  We do this to CHECK HOW TIGHT the lines are in the current setup.  If you commit to lining the entire boat and then inflate it and the tension is too high or low, you have a lot more work to undo.
  • If you are happy with the tension of the rope, deflate the boat to its previous sogginess and continue. If you ARE NOT happy with the tension of the perimeter line deflate the boat to original sogginess, undo the knots, adjust and carry on.

NOTE:  It is not a bad idea to do this every couple of d-rings to ensure all is on track.  We have learned from experience when rushing this process, it often takes 3 times as long

  • Once you have run the line around the boat and tied off all the knots it is time to secure the line at the end of the boat. Get the correct tension in the final section and tie off with a re-threaded figure 8 or bowline
  • Now cut any extra rope/webbing off the end of the system (leaving a good 4” – 6” of tail for any little slippage that my happen in the knots over the years). Once cut, use a lighter to heat the end of the webbing/rope.  This will melt away any frayed sections and will ensure the integrity of your system.

That’s it, you know have a safe and secure perimeter line setup on your raft.  If you have any meaningful leftover rope or webbing, you can set up a Bow Line with it to help you secure your raft when you are pulled up on shore.

See the great tutorial below from NRS on how to do that!