Gear Preparation

HOW TO SIZE AND SET UP A RAFT PERIMETER LINE

So, you've purchased a raft. But now you find yourself staring at all these unused D-rings on the outside of the boat. Wondering what to do with them? Well, they can serve multiple purposes. Primarily, they are used for attaching frames, seats, and platforms. They are also ideal attachment points for securing gear and drybags with locking carabiners, or for use in complex rescues. For those more adventurous paddle rafting or navigating whitewater, D-rings can be used to attach a full perimeter line. A perimeter line, also known as a "chicken line," is a key safety feature that allows people to hold on for balance in rapids or to re-enter the boat after an involuntary or voluntary exit.

To help you size and set up a raft perimeter line safely, we've answered some of the most frequently asked questions that often come up during the process.

PERIMETER LINE QUESTIONS WE OFTEN RECEIVE:

• What can I use for a perimeter line?
• How much rope do I need for my perimeter line?
• How do I set up a perimeter line safely?

WHAT CAN I USE FOR A PERIMETER LINE?

We recommend either a 5/8" braided polypropylene rope or 1" tubular webbing. Each option has its pros and cons, but they ultimately perform similarly. The choice comes down to personal preference and how the line can enhance your experience on the water.

5/8” Braided Polypropylene Rope

Pros: Resistant to sun damage and rotting (when kept wet for extended periods). Easy to hold, handle, and tie knots in.

Cons: Polypropylene is a dynamic line and will stretch over time. When re-entering your raft, especially if you don’t have knots tied at every D-ring, the line will flex and lose some of its effectiveness.

1” Tubular Webbing

Pros: Tubular webbing is a static line, meaning it has no flex in its system. It has a higher breaking point, and its bright colors make it easy to see from the water. Additionally, the webbing lies flatter against the boat, reducing the likelihood of foot entrapment or getting caught on a knife or other PFD accessories when climbing in.

Cons: While tubular webbing has its benefits, it can be much harder to hold onto than braided rope. It is also more susceptible to sun damage if exposed to strong UV for extended periods. Additionally, it can be harder to tie knots when setting up your raft and more difficult to untie when it's time to adjust or replace the line.

HOW MUCH ROPE DO I NEED?

Things To Consider: The length of your raft and if you plan on tying knots in each D-ring.

The short answer is: if you are tying knots in each D-ring, take the length of your raft, multiply it by 3, and add the width multiplied by 2. If you are not tying knots in each D-ring, multiply the length and width of the boat by 2 and add them together. This will give you the approximate length of rope or webbing required.

The 13 and 14-foot rafts we typically deal with have 10 D-rings, so calculations are based on this. If your boat has more D-rings and you plan to knot all of them, you will need to increase the amount of rope or webbing to buy accordingly.

Example | NRS OTTER 130 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. Keep this in mind and consider purchasing a little extra webbing or rope to ensure you have enough.

Handy tip: Extra webbing or rope can be used as a quick access bow line once the boat is in use! Check out this quick video from NRS on how to rig a bow line.

HOW DO I SET UP A PERIMETER LINE SAFELY?

There are numerous approaches and perspectives on setting up raft perimeter lines, but we'll focus on our preferred method: tying knots in every D-ring.

We opt for this method primarily for safety and functionality, tailored to our specific needs—family multi-day whitewater raft trips and gear boating with kayak support on whitewater trips.

Safety Considerations: Knotting every D-ring reduces potential slack in the system, minimizing entrapment hazards both for individuals and in navigating external river hazards.

Functionality: Without knots in all D-rings, slack can lead to insufficient tension, making it difficult or impossible to re-enter the raft unassisted after falling out. Knots in every D-ring provide the necessary tension, enhancing the likelihood of successful self-recovery.

What you'll need

• 5/8” braided rope or 1” webbing (sized for your raft)
• A sharp knife
• A lighter
• Raft (with D-rings)
• A boat pump

The Proccess

• Start by partially inflating the raft to approximately half pressure, so it still looks soggy. This allows room for the raft to expand.

• Tie the line to the lead (front) D-ring. We use a re-threaded figure-8 (Click here for tutorial) or bowline (Click here for tutorial) for this starting knot.

• Run the line to the first D-ring in a fairly straight, semi-taut line. Once you've determined the correct length, tie a clove hitch (or use an overhand knot or other preferred knot) onto the D-ring. Repeat this step on the next D-ring.

• Pause and get your pump to fully (or almost fully) inflate your raft. This step is crucial to check the tension of the lines in the current setup. If you continue to line the entire boat and then find the tension is too high or low after inflation, it will be more challenging to adjust.

• If you're satisfied with the tension of the rope, deflate the raft back to its previous "soggy" state and proceed. If you're not satisfied with the tension of the perimeter line, deflate the boat to its original state, untie the knots, make adjustments, and then continue.




It's good practice to do this last step every couple D-rings to ensure everything is on track. From experience, rushing this process often ends up taking three times longer.

• Once you've wrapped the line around the raft and tied knots at all the D-rings, it's time to secure the line at the boat's end. Make sure the final section has the right tension and secure it with a re-threaded figure-8 or bowline knot.

• Trim any excess rope or webbing, leaving about 4 to 6 inches for potential knot slippage over time. After cutting, use a lighter to melt away any frayed sections and ensure the integrity of your raft perimeter line.

• That's it! You've now set up a safe and secure perimeter line on your raft. If you have any leftover rope or webbing, consider using it to set up a bow line to help secure you to the shoreline.

Check Out This Video From NRS: How To rig A Bow Line >