# Oar length and other questions



## BilloutWest

*Ths formula doesn't work for whitewater*

.
.










The Oar Length Formula Step-by-Step

1) Measure pin-to-pin span for the rowing station

2) Divide span by 2 and add 2" to compensate for freeboard

3) Divide by 7.

4) Multiply by 25 to get oar length in inches.

5) Divide by 12" to get oar length in feet and tenths of inch.

6) Round to nearest whole inch.

*Oars & Rowing by Clint Chase*


----------



## BilloutWest

This one does for some:

Formula: Distance between the Oar Locks X 3 - 6", Divided by 2, Divide by 12 to get feet. 

Example: 72" X 3 = 216 - 6" = 210 divide by 2 =105, divide by 12 = 8.75 ft oars.

==========

This general guide from river connections at:
Riverconnection.com - Articles - Boating Gear - Choosing the correct Oar size for you.
on oar sizing

===============



> Oar length is largely a matter of personal preference; we can help you wade through some of the specifications you should consider.
> Important specifications include boat type and size, gear and passenger load, water classification, skill, and your preferences as the oars person.
> Frames are measured by various manufactures differently. So the outside edge of the frame may have a different measurement for one company to another. This can also change with double railed frames. It is best to use the inside width of the Raft, Cataraft or pontoon Boat plus one tube size. Always round up the nearest ½ ( 9.3 would be 9.5). Drift boats are measured by the widest width at the bottom (from chine to chine).


----------



> FRAME WIDTH
> 
> RECOMMENDED OAR LENGTH
> 54" 7.5 feet
> 60" 8 - 9 feet
> 66" 9 - 10 feet
> *72" 10 feet *


* (Wait a minute; They're formula for 72 inches says 8.75 feet)*

Their contact number has been disconnected.


----------



## BilloutWest

So the formula used by smooth bottom boaters in post 2 says 11.3 foot oars.
The formula by River Connections says 8.75 foot.
The general rule table by River Connections says 10 foot.

= = = = = =

What works for you?

Your oarlock with and oar length and why you think that is.

Thanks


----------



## MT4Runner

Quoted from the other thread:


cataraftgirl said:


> To BilloutWest .... there is no one answer, and you will blow a blood vessel in your head by trying to figure it out. Get a boat, get a frame, get some oars, and spend all winter with it in your garage (or living room) trying to make it all work to your liking. Then put it all in the river, and start tweaking it yet again. This is the life of a river rat.


Pretty much!


I saw another table that compared boat length to oar length, but in general, boat length/boat width/frame width end up being somewhat proportional.

There have been numerous threads on the topic and no clear consensus. Generally, ~8' for 12' boats, 8.5-9' for 13' boats, 9-10' for 14-15' boats and 10-11' for 16-18' oats. Longer for exceptionally wide frames or large tubes.

Personal preference overrides all "rules".


----------



## cataraftgirl

Here is my oar story, starting with my cataraft. No I don't think it matters if you have a cat or a raft. Frame size, raft or cat size (length, width, tube size), seat height, tower height, rower size (legs, arms, torso, gender), rivers run (big water, small & technical) are just some of the variables that determine oar length.

Back to my Cat story. I was happy with my oar set-up for many years, until I added a second dry box to my frame, and put a AAA flip seat bracket over one of the dry boxes, thus raising my rowing position. Oars felt short. Longer oars purchased, taller oar towers purchased to lean outward, giving more width, and allowing for a balanced oar position. Happy Cataraftgirl. 

Got my new small Hyside raft - 12 ft. X 6 ft. X 19 inch tubes. 54 inch NRS frame which fits this raft perfectly.I looked at the NRS oar sizing guide, and decided the recommended 7.5 ft. oars sounded too short. Got 8 ft. oars. Got them set up, and they didn't feel right. To enter the water and get a power stroke would mean the oars would come up rather high. Not a good power position for rowing. Bad for the shoulders. Many years ago, a long time rafting guide told me that your oars should allow you to push at the same level as a boxer throwing a solid jab punch. I also noticed that most of the Hyside Mini-Max folks were running 8 ft. oars with a 48 inch frame on that smaller boat. That, combined with my gut feeling, combined with my "too short oar" experience with my cat, led me to return the 8 ft. oars, and get 8.5 ft. oars. With taller towers, wider spacing of the oar locks, and longer oars, it now feels right. Happy cataraftgirl. 

And there you have it. The oar gospel according to cataraftgirl. Amen. Your mileage may very. Row your own rig. Go with the flow.


----------



## BilloutWest

I'll get beat up for this.

Rather than seat placement dictated by drybox height and oar specifics following. It should be the oar lock placement, oar length, balance, fulcrum and all that should be optimally placed for a given rower. 
They dictate the seat height.
THEN the drybox height etc follows.

Should follow .............

Some compensation can be gained by having higher oarlocks ....... sure

= = = = = = = =

I think there is a lot of difference between raft and cat, with regard to degree of difficulty. Even a bucket boat has issues with turbulence.

Contrast a scull to a row boat to a cat to a self-bailer.
At some point all that resistance will affect what oar 'system' is practical.
Especially when looking at rowing all day into the wind on a SW River.


----------



## Avatard

BilloutWest said:


> I'll get beat up for this.
> 
> Rather than seat placement dictated by drybox height and oar specifics following. It should be the oar lock placement, oar length, balance, fulcrum and all that should be optimally placed for a given rower.
> They dictate the seat height.
> THEN the drybox height etc follows.
> 
> Should follow .............
> 
> Some compensation can be gained by having higher oarlocks ....... sure
> 
> = = = = = = = =
> 
> I think there is a lot of difference between raft and cat, with regard to degree of difficulty. Even a bucket boat has issues with turbulence.
> 
> Contrast a scull to a row boat to a cat to a self-bailer.
> At some point all that resistance will affect what oar 'system' is practical.
> Especially when looking at rowing all day into the wind on a SW River.


That's all fine and all but if i wanted to row crew i would live next to the Charles

Practical considerations usually dictate how your seat height is created

Like you got this killer drybox from a friend for $150. Or you want to go on weeklong trips and you have to sit on your cooler

Its usually easier to swap out your towers and change your oar towers than to try and find that perfect setup that you nailed after three years of careful contemplation

That's why I row with friends and check out their boats. Mine feels pretty comfortable but I'm never know if I'm there yet unless i keep trying something different


----------



## BilloutWest

Reinventing the wheel has its merits.

Learning from others the same.

========

My wife pointed out that its not called rowing.
Its floating.
Mostly its people that can't or don't want to backpack because of the work.
That applies to me at this point in my life.

The river does the work.
Rowing is a side issue.

=========

However. If one can cut back that nasty work even more its not a bad thing.

The people from the crew world have a lot more knowledge about rowing than we.
They use their thighs.

Using legs with a sliding seat allows not just a stringer stroke but also a wider arc for the oars.

At a minimum one should not spend _more_ money on a fixed rigid back seat that stops leg movement. That is not a killer deal.


----------



## cataraftgirl

Rowing a raft in whitewater and rowing crew are two totally different animals. Crew is about moving a streamlined craft down a river in a straight line as fast and efficiently as possible. Whitewater rafting is about moving a less than streamlined craft, that's loaded with gear, adults, dogs, kids down a river in a semi zig-zag fashion, avoiding rocks, holes, and huge waves. Speed and efficiency aren't always the goal in whitewater. Mostly it's about control, which may correlate with power, or may correlate with well timed & placed oar strokes. 

As for the frame, and positioning your oar towers for maximum efficiency.... there are often too many variables to consider that make that difficult. As Avatard pointed out, often gear acquisition is done by spur of the moment purchases, not always well thought out plans. Like a killer deal on something that you find at a gear swap. Some folks who are just getting started in whitewater rafting pick up a used boat and frame, and must live with the hand they are dealt with the frame. In the case of my small raft. I got it mainly for easy float & fishing weekends, but I'm taking it on a week long whitewater trip next week. So the frame configuration is different than it would be for fishing. Cross bars and oar towers are moved around. Having the ability to reconfigure the frame suits me, but not everyone would like that.


----------



## MT4Runner

[QUOTE="cataraftgirl]Whitewater rafting is about moving a less than streamlined craft, that's loaded with gear, adults, dogs, kids down a river in a semi zig-zag fashion, avoiding rocks, holes, and huge waves. Speed and efficiency aren't always the goal in whitewater. Mostly it's about control, which may correlate with power, or may correlate with well timed & placed oar strokes. [/QUOTE]
Exactly.
Rarely do I ever take more than three or four strong parallel strokes at once (unless I'm rowing into the wind). More often, it's a lot of right-forward/left-back, or dig one blade in the current and hold firm while you row the other madly in an aerated hole or eddy. Even ferries only get a few sequential strokes before a corrective stroke is needed. A sliding seat is going to distract as much as help.

Even with the ability to build my own frame, the reality is that others will row it, too, so I shoot for something that fits me and still works for my friends. (I like to have alternate rowers in my crew so my own ass can be in a kayak!)

Build your frame modular and do tinker with it all season. Theoretical discussions are fun, but when the water flows, empirical evidence is best!


----------



## BilloutWest

MT4Runner said:


> Exactly.
> .........
> 
> Build your frame modular and do tinker with it all season. Theoretical discussions are fun, but when the water flows, empirical evidence is best!


I'm saying don't run from the math.

Just because its complicated.

THIGHS.

Being able to move a whitewater boat fast and efficiently is important. If two quick strokes can get you 4 more feet that is a big deal. Being able to row at an optimum efficiency is still important even if one only has to accomplish 20 important short rowing strokes a day.

==========

Does anyone know of anyone with a rig with a sliding seat for the captain?

THIGHS.


----------



## geobucket

Well, I did row crew in college, and I have absolutely no desire to have a sliding seat in any of my rafts. Yes, it would make for superior rowing, but the considerations are just a lot different. Cargo, access, etc. Rafting is more about maneuvers than moving from the start to the finish line.

BTW, I row a 14' raft, 60" NRS CO frame w/ 8" mounts, 9' oars. Pretty vanilla setup, sitting the cooler. My little Puma is basically a scaled down setup with 8' oars, though I am going to try and mount a low-back seat someday.


----------



## Avatard

geobucket said:


> Well, I did row crew in college, and I have absolutely no desire to have a sliding seat in any of my rafts. Yes, it would make for superior rowing, but the considerations are just a lot different. Cargo, access, etc. Rafting is more about maneuvers than moving from the start to the finish line.
> 
> BTW, I row a 14' raft, 60" NRS CO frame w/ 8" mounts, 9' oars. Pretty vanilla setup, sitting the cooler. My little Puma is basically a scaled down setup with 8' oars, though I am going to try and mount a low-back seat someday.


Apparently you are wasting a lot of effort by not having that optimized.


----------



## BilloutWest

Avatard said:


> Apparently you are wasting a lot of effort by not having that _optimized_.


Let's go with _superior rowing_.

geobucket;
Cargo access would be a problem.
No more of a problem then those with a fixed seats with an upright back.
But a problem.

I still like the opportunity to maneuver with more power.

Do you feel that a sliding seat would hinder a turn? Oars going opposite ways or just one lazy oared turn?


----------



## lhowemt

How the heck would you brace with a sliding seat? Most of my rowing entails pushing with my legs and butt, to hold me in position. My back then does most of the work, and my arms fine tune it.

Cat oars are so different because there is a lot more frame width variability, and tube size variability, then with rafts.


----------



## Avatard

I've spent more effort on this thread than i did dialing in my setup. First day on the river today!!! God i friggin hate work and home improvement projects


----------



## BilloutWest

lhowemt said:


> How the heck would you brace with a sliding seat? Most of my rowing entails pushing with my legs and butt, to hold me in position. My back then does most of the work, and my arms fine tune it.
> 
> Cat oars are so different because there is a lot more frame width variability, and tube size variability, then with rafts.


The sliding seat wouldn't slide forever.
It should have a higher back to brace against and for comfort just floating along.
The range could be set less than each captains leg length. Setting variable stops wouldn't be a hard engineering problem. Instead of a set screw, go with wing nuts.

Currently, most do not have a rock solid brace capability as they are on a flat cooler or drybox with a pad.

One can see this in the recent Illinois video:
http://www.mountainbuzz.com/forums/f11/illinois-video-from-last-weekend-47395.html#post313272

The Captains are bounced around a fair bit. This is exaggerated some by the very poor foot bracing with the Captains foot bay overloaded.

= = = = = =

This is part of the reason there are captains seats with backs on some rafts is the ability to firmly brace. The downside here is that removes the legs from oar power.


----------



## BilloutWest

A flat seat doesn't allow for secure bracing.

A fixed Captains seat with back doesn't allow for leg strength being applied to the stroke.


----------



## lhowemt

I use a low back and brace like crazy on it. I don't like high back, it removes the back from rowing. Even though I'm quite strong, I don't have the arm strength of guys who can get by w high back easier. And I like to surf, which often entails big leans back. Flat water a moving seat, yeah I can see the benefits. Whitewater, I don't.


----------



## BilloutWest

*Feasibility study*



lhowemt said:


> I use a low back and brace like crazy on it. I don't like high back, it removes the back from rowing. Even though I'm quite strong, I don't have the arm strength of guys who can get by w high back easier. And I like to surf, which often entails big leans back. Flat water a moving seat, yeah I can see the benefits. Whitewater, I don't.


I'm thinking the way to do this is with a *butt channel*, then a firm lower stop and a flexible upper back.

Closed cell foam. In a glacier valley shape for me. But not too deep. Thinking 3 inches.
Smooth nylon seat.
Cordura traction back. 1,000 denier.
Lower back a firm rigid stop for bracing. Maybe start with a 12-15 inch slide range.
Flexible upper back allowing for naps or even leaning back to finishing a stroke.

No sliding seat.
Just a spot for ones seat to slide. 
A place for everything..........

Avoid bay access issues.
Front of seat channel to be securely hitched.
Could be set up with cams to tighten or loosen in 10-15 seconds for changing captains. For those long rows in the SW.

The channel angled slightly down. For ergonomics and natural draining.

=========

The support for the butt channel sides could be a firm foam or something even more rigid. Broad shoulders with no cliff on each side.
Not sure what would work best for the flexible upper back under its one layer of foam. Needs to be springy and have a great memory.


----------



## Avatard

Tried to post a pic of my butt channel


----------



## lhowemt

The sides are important for bracing also, not just the back. Windy desert rivers might be a great place to get the legs into, sure sure. Some catboaters like to use a board, instead of a seat, and heck some people just sit on boxes w no seat. I'd think a lockable track is a better idea.


----------



## Avatard

lhowemt said:


> The sides are important for bracing also, not just the back. Windy desert rivers might be a great place to get the legs into, sure sure. Some catboaters like to use a board, instead of a seat, and heck some people just sit on boxes w no seat. I'd think a lockable track is a better idea.


I'd rather have comfort of some padding. if its windy I backrow. I think a good set of rearview mirrors would be a better low tech solution than a complicated mechanical sliding seat like at the gym ...


----------



## BilloutWest

*butt channel concept*



lhowemt said:


> The sides are important for bracing also, not just the back. Windy desert rivers might be a great place to get the legs into, sure sure. Some catboaters like to use a board, instead of a seat, and heck some people just sit on boxes w no seat. I'd think a lockable track is a better idea.


Perhaps a generous crescent moon shape at the terminus of the glacial valley?

It would go a little wide but its there for that unexpected in flight turbulence.
Just the low back _this is your captain brace brace brace_ stop.
Higher sides than 3 inches might just do the job also.
======

Because of difficulties with building a durable sliding seat I'm thinking of playing with the butt channel concept first.
It would offer the option of essentially no seat in case of issues or preferences.
No moving parts in the first attempt.


----------



## BilloutWest

*Time to get beat up again*

Does anyone know of any rafter or cat'r, no offense - none taken, that intentionally starts with two different sets of oars?

Say one set longer.

Outside of the initial emergency this means a total swap out is necessary should one oar break.
In effect there is only one spar oar even though two are carried.

The reason for this could be two distinctly different sized captains or occasional dropping back to a shorter set for a day of narrow chutes.

=======

Just a question.


----------



## cataraftgirl

BilloutWest said:


> Does anyone know of any rafter or cat'r, no offense - none taken, that intentionally starts with two different sets of oars?
> 
> Say one set longer.
> 
> Outside of the initial emergency this means a total swap out is necessary should one oar break.
> In effect there is only one spar oar even though two are carried.
> 
> The reason for this could be two distinctly different sized captains or occasional dropping back to a shorter set for a day of narrow chutes.
> 
> =======
> 
> Just a question.


Oars are way too expensive to carry two sets for one boat. I have one set/size for my larger cataraft, and one set/size for my smaller raft, plus spares for each. That's all I need. Not many trips where the character of the river changes dramatically enough to warrant two different oar sizes.


----------



## mrett

Will occasionally take 2 sets of different size oars. 9' & 9'6" Short set for the technical section, longer set for the big stuff. Think N.Fork CalSalmon and Nordheimer run.


----------



## slamkal

BilloutWest said:


> Does anyone know of any rafter or cat'r, no offense - none taken, that intentionally starts with two different sets of oars?
> 
> Say one set longer.
> 
> Outside of the initial emergency this means a total swap out is necessary should one oar break.
> In effect there is only one spar oar even though two are carried.
> 
> The reason for this could be two distinctly different sized captains or occasional dropping back to a shorter set for a day of narrow chutes.
> 
> =======
> 
> Just a question.


Like 1' oar extensions? I could see on long trips like the Grand Canyon that the difference in draft during the trip might warrant two different lengths


----------



## BilloutWest

slamkal said:


> Like 1' oar extensions? I could see on long trips like the Grand Canyon that the difference in draft during the trip might warrant two different lengths


Do you have oars where you can change the 'button/collar' location?

Or just grin and bear the balance change?

==========

I would think the longer oars also for any upcanyon wind days. Regardless of draft. 
Is that out to lunch?


----------



## slamkal

BilloutWest said:


> Do you have oars where you can change the 'button/collar' location?
> 
> Or just grin and bear the balance change?
> 
> ==========
> 
> I would think the longer oars also for any upcanyon wind days. Regardless of draft.
> Is that out to lunch?


I never did a trip longer than 7 nights, so no need to. If you count food consumed minus weight pooped its probably 100 lbs lighter at the end of a trip

I ran 11' oars (no C/b) on a MFS at 2.1' last August. No issues with hitting the oars against boulders, being too big, or not efficient enough rowing. 

The water can always take all the force i can deliver. Its comfortable and feels right. A lb or two of counterbalance would be nice. Maybe epoxy a stack of washers down the shaft


----------



## 2kanzam

I just wanted to chime in with my somewhat unconventional set-up and all of your posts had me really re-thinking my oar length this winter. I was given the set of 10’ oars that I have, so I had just figured I’d deal with it or cut ‘em down if I had to for either my 14ft Hyside or my 14’ Revolution which are both virtually the same size.

I have a 60” NRS stern frame, I believe 6” towers (could be 8, I keep meaning to measure) and I’m 5’9”. Most of the formulas say I should have 9-9.5’ foot oars for my set up (BilloutWest’s first one actually works out to 10’). And given my frame the 10’ oars can’t get too close to the 2/3 to 1/3 “rule” so I counter balanced them with 2.5 lbs on each stick.

With the counterbalance running a stern rig it is quite comfortable for me. I was just looking closely this weekend while on the water and I would be hard pressed to lose 6” off the length without adjusting my stroke to make the blade dig deeper….I’m guessing that these formulas typically don’t account for the tube’s kick for a stern rig….and I don’t think too many of you run a stern frame, so I guess that is making the difference? 

My most unconventional set-up is when I’m hauling gear. I move the stern frame up to where the seat is about where the rear thwart would be. The seat part of the frame sits up on a wooden bench I made which puts the platform the frame sits on at 5 ¼ in above the tubes and the seat is about 7-ish inches above the tubes (basically 2 “pillars” made of 2 pieces of hexagonally cut 2x8s stacked on each side-with a single 2x8 spanning those pillars and the width of the boat)

3 Waterproof barrels are suspended from under the bench off the floor and it gives me a nice flat surface on top to strap a dry box and tackle box to that makes getting into them easy. A cargo carrier is suspended from the back of the bench to the rear and rear/side d-rings and my cooler and extras suspended in a single bay in front of the captain’s bay. The single cargo bay stops short of the front thwart, which I leave in place, because the GF likes a cushy place to sit. 

This all keeps the geometry pretty close to the stern rig geometry so I don’t have to adjust anything and 10 foot sticks still work fine for me.

Someday I’ll post some pics of my hillbilly engineering.


----------



## BilloutWest

2kanzam said:


> With the counterbalance running a stern rig it is quite comfortable for me. I was just looking closely this weekend while on the water and I would be hard pressed to lose 6” off the length without adjusting my stroke to make the blade dig deeper….


I would expect none of these formulas correlate very well with the high seat stern mount.

Two primitive thoughts. Beat me up.

Rowing more vertically has drawbacks. Shallow water or hidden hazards in mirky water.

In a more normal captain's height going to shorter oars can mean some rock avoidance and easier shipping. Understood.

But one loses not just leverage with shorter oars. The arc of the shorter oar is tighter and it covers more degrees of the circle with the same range of movement by any given oarsman. That is bad. 
A greater portion of the time the shorter oar is pushing somewhat away from the boat and not in the optimal, there is that word again, right angle to the boat. 

============

Does any oar manufacturer put out a blade like the grooved flippers?










I'm just wondering about being able to use a smaller blade because water is held some and not allowed to slide off the sides as much.

Just asking. I don't even know if my reasoning on any of this post is correct. Just my mind wandering.

I have feelings too so go light.......


----------

