Lengthening oars

I have two wooden oars which are about 1.8 m (6') long. They are too short to be usable for anything other than short day trips. The calculation in Roger Barnes' book The Dinghy Cruising Companion suggests they should be about 2.4m (8') on a Mirror. I was thinking of lengthening the shaft by using some sort of metal tube as a sleeve. Has anyone else lengthened theirs? How did you do it? It may ultimately be cheaper to buy new oars, but If I can use what I already have, I would prefer that. I am aware that 2.4 m may be too long to store easily on a Mirror, so I may end up compromising on the length.
Thank you!
John
Red Kite
53814

DavidH's picture

Old post I know, but I'm new here and trying to make up for lost time!

I worked out the ideal length for oars for the Mirror at nearer 9 than 8 feet. You will get away with scarfing an extra length of wood, but a metal sleeve is probably going to bend at some point.

On paper you want 6 foot or so of oar outside the boat and the other (nearly 2 foot or so) inboard. Your 6 foot oars will be thinnish in diameter, which is good, because if you scarf-joint some thicker diameter wood to the handle ends, and fashion new handles on the new wood, your oars will be much more balanced, which makes the boat easier to row. An epoxied scarf joint will be at least as strong as the rest of the shaft (which I didn't believe until I worked with scarf joints and epoxy, but its true).

On the oars fitting the boat - can't comment, except to say they will fit as long as you don't mind some oar outboard forrard.

Let me know how you get on, because I have old oars to alter once my boat arrives.
Cheers,
David

DavidH's picture

My oars are also 6'. I was surprised at how well they worked in Lutra on Saturday - much better than I would have thought. The reason, I believe, is this: The Mirror is a shallow-V planing hull from 6" back of the foredeck - which is where all the rowing action takes place. There is simply not the drag associated with pushing a more traditional keeled dinghy through the water. If 6' oars prove to be efficient (over a longer distance than I did on Saturday) then it will solve a potential problem. That of where to store longer oars out of the way in a fairly confined cockpit.

David
Lutra

curlew's picture

I have very short oars on my Mirror, which is forced on me due to the stowage problem, but i can row as fast as a kayak.
david
Curlewlem

DavidH's picture

You confirm my findings David, both as to the suitability of short oars for the Mirror, and the lack of stowage. I'll do a quick test at the weekend with the GPS to see what speed this 70 year-old can get up to and maintain over a measured distance under oars.
I also found that the Mirror rows backwards easily, and turns on a sixpence.
David
Lutra

PuffinInTegel's picture

Some weeks ago, I took my boat out on a (forecast) windless afternoon and rowed around two of the islands on our lake and out of curiosity, measured the path on Google Earth - 1.65 nautical miles. Unfortunately I did not look at the time, but it must have been around 3/4 of an hour so that works out at roughly 2 knots, which includes stopping briefly to look for the beavers and rowing against the wind on the last 300 metres or so - a wind which sprung up unexpectedly just after I'd turned the corner to go on the home stretch :-{( .
We could start a new topic thread in which we can put up more detailed reports on our experiences, including the length of our oars, distance rowed, weather conditions and times taken.
I am really interested in the subject as there are stretches of our waterways on which sailing is prohibited and dinghy cruisng would therefor involve rowing if I want to travel on these, Jack de Crow style.

DavidH's picture

Good idea.
My observation is that unlike a normal dinghy hull the Mirror hull shape is conducive to short oars, which are also easy to store inboard. The downside of the Mirror hull seems to be that you stand up anywhere near the front deck at your peril!
I have the profile mapped out for making my oars slimmer. This won't apply to the oars supplied with a new boat, since mine are cut-downs of bigger oars.
The plan is to re-shape my oars over the Winter, and do a GPS speed test with short oars over a measured length of water in the Spring. I do this routinely on the kayak in a time-v-distance format.
Cheers.
David
Lutra

Red Kite's picture

Thank you All. I'll stick with the oars at their present length for a while and see how it goes.
John
Red Kite 53814

curlew's picture

It is true that the boat is unstable if you stand right at the bow. However, if you stay close to the mast and stay low it is OK. I use the foredeck for accessing my tent, so it is possible if you are careful.
If you always imagine the water line of the boat, looking from above, that is the stable area you can stand in. If you put the centre of gravity of your body outside that perimeter, for instance if you sit on a gunwale with legs over the side, you risk capsize. david

DavidH's picture

Thank you.
David
Lutra