Dinghy oar length

[Roger Long]

My used 8 ft dinghy has always had 5 1/2 foot oars. I don't expect much from rowing an 8 foot boat but someone pointed out that they were way too short and I realized that I do feel sort of like a daschund when I'm rowing it. OTOH the oars fit nicely under the thwarts and are easy handle getting in and out of the dinghy at anchor.

The Shaw and Tenny web site says I should have 7 1/2 foot oars for the 48" oarlock spacing and they will just fit in the dinghy on top of the thwarts so I went to buy some. Wow, did they look long for such a little boat. The selection guide on the oar rack at Hamilton said I should be buying 6 foot oars so I left empty handed to ponder it some more. If 6 foot is right for a short boat that isn't going to glide, I'm not sure I'm going to pay 100 plus bucks for 6 more inches and give up the stowage convenience. The S&T formula is for boats that are real rowing craft. I wonder if the Hamilton formula is more realistic for tubby little boats?

I lean towards the convenience of the shorter oars but, if I ever had a hard chance getting back to the boat at anchor in a sudden blow or had to make a long row home after a sinking, I might be glad of optimum oar length.

Any thoughts from those of you who aren't using who aren't using the gasoline burning style of oars?

 

[Bill Roosa]

Row boat geraing

Short oars are like low gear, they let you get lots of force but you have to row fast to get any speed on. Long oars are like high gear, not as much mechanical advantage but man can you get the boat moving without rowing fast.
FWIW, my observation is that it would have to be blowing pretty hard for me to not be able to get up to speed (like starting in high gear) even with the lower mechanical advantage of long oars. That is way my 8' dingy has 8' oars. they stow neatly on the diagonal.
BTW they cost me $0.00 as I made them myself out of the left over material for the dingy mast and hull. I believe you could glue up some for under $10 of raw materials in an afternoon. Then epoxy coat and paint

 

[druid]

There are "rules" for length of oars, usually derived from beam rather than length. Try a websearch for "oar length calculation" or something. I have 7ft oars on my 8.5ft dinghy and they're pretty good. I could go to 7.5 if I overlapped the handles.

Of course, this is on a hard-shell dinghy (modified D5) - if you're talking inflatable you're probably better to get one of those hand-crank outboards...

druid

 

[MrBee]

For a small dinghy I don't think I would go the $$ for long Oars but S&T does make very nice Oars. I used one of their Sculling oars for my Seacoast gunning float and a set of Spooned Rowing Oars for it also.

Brian

 

[Ross]

Aren't the oar locks the fulcrums and the oars are levers? The force you apply to the oar handles is applied to the oarlocks. Longer oars will move you farther with each stroke but mostly it will be speed that is affected . I think.

 

[Old Skool Neil]

Another factor is how high you have to raise the inboard ends (handles) to get the blades into the water, a function of freeboard and oar length. Shorter oars = higher handles.

 

[Roger Long]

Shorter oars = higher handles.

Good point when there are a bunch of knees, grocery bags, ice, etc. in the way.

 

[Ron20324]

I recall a mag article by Pardee or Casey or such. It was suggested oars be 1.5 times the beam.

 

[Roger Long]

I recall a mag article by Pardee or Casey or such. It was suggested oars be 1.5 times the beam.

That's the same as the number on the Hamilton Marine oar rack. A picture is emerging here.

The Shaw & Tenny formula is a fancy way of saying 1.9 times the beam (assuming no outriggers and rounding to the nearest half foot). People who are rowing for it's own sake prefer that ratio. People who are just trying to get themselves, supplies, and crew back and forth to their boat tend towards the lower number.

I suppose I could split the difference which would mean 7 foot oars on my dinghy but now I would like to experiment before spending money on new oars.

 

[sailingdog]

It depends on the boat. Higher freeboard boats of the same beam are generally going to want longer oars than lower freeboard boats.

I use seven foot oars on my porta-boat, which IIRC has a beam of 5' and they seem to work fairly well. Longer oars would probably be a bit better, but more trouble to stow.

 

[Roger Long]

I use seven foot oars on my porta-boat...

That would be just about exactly the ratio I have with my current 5 1/2 foot oars. "Fairly well" and stows easily is exactly what I would say about them. Maybe I should just slap on a coat of varnish and obsess about something else, like how to spend the 125 bucks I just saved.

 

[zeehag]

i use the 6 ft oars walker bays come with---with the scooped paddles--lol--AWESOME---my neighbors have 6 ft oars and use with comfort and stow easily--i dont really seee any positive aspect to 7 ft oars--they are expensive and do no treally have any positive aspects to them. btw--i reside in my formosa on a mooring--no one has 7 ft oars--we use oars and rowboats every day of our lives----

 

[Rick9671]

dingy oar length

For a long row against a strong wind, I prefer longer oars, probably 7 foot. For short rowing distance and maneuvering in tight quarters, the shorter oars are easier to use.

My experience with the Walker Bay 10 footer is that it is very easy to row with the original equipment oars. However, the original equipment oarlocks and sockets wear out very quickly.

 

[Ross]

Re: dingy oar length

Oars are levers. within reason any oar will work. the ratio between length of oar insde the boat versus length of oar outside the boat determines how far the boat moves compared to how far your arms move. Paddles work on canoes but you hand becomes the oarlock and the leverage ratios stay pretty close to 1:1. They are handy though and that is why they are still used. You just have to decide what is most important to you. Long oars let you take long steps across the water but you can't exert much power. Short oars force you to take short steps but you get a lot of power.