Designing your raft frame.
What style & size raft do you want?
Would you rather have a raft or a cataraft? What length boat would be best? Every boat has its pros & cons. Are you doing multi-day trips or just day runs? What river stretches do you want to use the raft on? How much gear or how many people and dogs are you going to want to fit on your raft? How are you going to transport and store your set up? Your answers to these questions should help you decide on your priorities and steer you in the right direction to the style and size boat that would be right for you. For more on this topic, check out our choosing a boat guide.
What’s your budget?
Oars, and dry boxes, and coolers! Oh My! A good rule of thumb is to plan on spending 1 to 1.5 times what you spent on your raft, if you bought a new one, on the gear you’ll need to outfit it for multi day trips. It all adds up: frame, oars, cooler, boxes, straps, etc. And this doesn’t include a trailer! That said, you can be thrifty about assembling your set up by buying a used raft and/or getting the other gear a little at a time. There are a variety of ways to build up your ultimate raft while keeping within a budget.
Measure your raft
After you’ve decided on a raft and a budget, the frame designing can begin. You’ll need to make some measurements. The overall width of the raft, the inner dimension (tube to tube), the diameter of the tubes, and the measurement from the start of the rocker to the start of the rocker (aka the flat part of the boat tube) all come into play when designing a frame.
Single or double rail, deck or no deck, adjustable or fixed bars?
The combination of your budget and intended use is going to help you make these decisions. Single rail frames, such as NRS frames, one outer rail along the length of the raft, are often made to be broken down. These are versatile, affordable, and easy to transport. Double rail frames have an inner and outer rail and can be made with or without decking between the rails. This style of frame tends to be stronger and heavier than a single rail frame. It’s worth noting, a single rail frame may require different oar lengths than a double rail frame. Now’s also the time to think about if your want adjustable or fixed bars. People often think they need more adjustability than they actually end up using. More adjustability ultimately makes the frame weaker. We recommend having at least one fixed bar to "brace" the inner rails of your frame.
Boxes and coolers
Again, how you’re planning to use your raft and your traveling preferences are going to dictate these next details of the design of your frame. Are you usually on the water with other boats or do you travel solo? Will you be doing trips on permitted stretches of river that require you to have certain gear? How do you plan to pack and rig the things you will be bringing? How much cooler storage will you need? What kind space for kitchen supplies will you need, and do you plan to store those supplies in dry bags, rocket boxes, a bigger size dry box? What are you planning on sitting on? You’ll need to know the dimensions of any boxy gear that’s a fixed size that you’re going to have in your set up.
Ideally the width of your cooler is close to the inner width of your raft, isn’t more than 4-5” above your frame’s cross bars and can hold ice for the length of time you’ll need. An easy way to calculate a good cooler height is to shoot for getting a cooler with a height that’s less than 85% the width of your tubes, i.e. 18” tubes = 15” tall cooler, 24” tubes = 20” tall cooler. This formula tends to work for self-bailing rafts and catarafts, with bucket boats you may have a little more room. If your cooler is in a bay adjacent to the footwell bay, and/or you’re using it as a seat, keeping the height to a minimum can help with your rowing geometry, which makes a difference in how the boat performs, as well as prevent you hitting it with your knuckles. You’ll also want to make sure you’re not going to have any clearance issues with your cooler’s latches and the frame’s crossbars or any other items that might get rigged close to the front of the cooler.
As for dry boxes, you could spend a little more and get custom sized boxes or you can go with stock sized dry boxes. A stout dry box can serve as a kitchen box, dry food storage, and a great seat for passengers or to row from. When planning for what size dry boxes you might need, think about the inner dimension of the box and what you will store in it, as this will dictate the box’s dimensions. If you don’t already have dry boxes, think about if you’d rather have 2 smaller more easily transportable boxes or one big, frame width sized, coffin like dry box. And just like with coolers, it’s best to rig your boxes no more than 4-5" above the deck of your frame. A standard height for a dry box is 15”-16.5", with the tabs set at 11-12” up.
To Hatch or Not to Hatch
You also you might want to think about having a hatch/drop bag combo bay in your frame. For long trips, this option can serve as a great catchall for all your hard to rig gear. For many day trips, a hatch can be a permanent storage compartment for the "don't forget it" gear like life jackets, pump, repair/ first aid, spare PFD, etc. The hatch, when it’s down, can serve as a passenger platform, deck space, or sleeping area. It can also be made to be removable so as to double as a table, which is good but could also be bad, because when you want to sleep on your boat, the hatch might be being used as a table in the kitchen. If you are planning on rigging down a "paco" type pad to your hatch, it is good to make the hatch the width of the pad, to keep it from bunching up under your rigging straps. For the best overall strength, we recommend that your hatch bay be a fixed size.
As part of the design process, we can work with you to help you to determine what size footwell you need. Your height, if you are a pusher or a puller, and what gear you’ll have rigged in the area all come in play in this decision. A 22"-26" footwell seems to be ideal for most people. Having a rigid footwell helps as a space to carry more gear and serves as a solid platform for moving in and out of the center area of your raft. An important safety issue about footwell size is the swing of the oars as it relates to other passengers on the boat. The more you compress your footwell, the more it brings passengers sitting in adjacent bays into the arc of a swinging oar.
Oar Size/ Length
The length of the oars you will need is determined by the measurement from oarlock to oarlock. Sometimes the wider the frame, the longer the oars you will need. It is good not to purchase oars until you know the overall width of your frame. There are times when a single rail frame oar length differs from a double rail diamond plated frame. The standard rule of thumb is to figure 1/3 of your oar length is from your oar tower in and 2/3 is from the oar tower out.
If you do any boating on desert rivers, you might want to think about adding some shade to your boat. Umbrellas are better than nothing, but once you try a bimini you may never go back. Even if shade isn't a priority for you right now, maybe you need some time to save money for this addition, while you are designing your frame is a good time to plan for places for umbrella holders or bimini mount slots.
It is normal to want to make all kinds of changes when you get a new boat, and we look forward to helping you make those changes happen. That said, before you give us some your hard earned money, we suggest you spend some time getting to know your boat as it is currently set up. After a couple trips, you will have a better idea of what you want to change, as well as a better idea of where those changes lie on your priority list. While we would love to sell you some cool custom thingy, that may not be the best way for you to start out with your new boat. Taking the time to figure out which bay you want your cooler in, what your passengers may be sitting on, what you may be sitting on, etc., is time well spent as well as good, fun, research.
The design phase is the time to think through all the details.
If you are ready to talk about designing your raft frame, please contact us.
For more pictures of custom raft frames, check out the gallery page.
You also might want to check out this video about designing a raft frame.