Thread: Seagull vs MSD

Originally Posted by keyhavenpotter

And just how good is this video, as a great advert for balanced lug rig and Phoenix III

YouTube - Light wind

Brian

Ross Lillistone AKA Tricky Dicky

Originally Posted by keyhavenpotter

Can you do this in a Seagull or MSD?

Great picture for a rowboat



Brian

Brian I havnt tried sitting like that. I will next time I am out. I dont think it would be a problem but I notice from the photo that flint transom is clear and MSD isnt really clear of water, but remember MSD is flat bottomed
Rowing is quite comfortable in MSD now I modified the skeg ( see the build thread) It tracks really well and glides beauitfully. I still should make proper length oars but probably wont. I should have put a bit of glass tape on the gunwhales for protection because they have taken a few bumps and have come second. All my fault and fixable.
I am using the rowboat at least monthly, mostly on Wivenhoe, which is the next dam down from the one where the Flint photo was taken and looks similar but without the powerboats. I dont own a GPS to record distance or speed, but I have passed electric powered tinnies and I would much rather be in a well designed rowboat than an aluminium tinnie with only electric power in anything rough.
I have also built boats stitch and glue and I am still inclined that way, provided you can easily reach the seams from the side. It is easy to bog in great heaps of thick epoxy at arms lenght but bloody hard to clean up, especially at the tack between stitches stage when the structure shouldnt (I should say MUST not) be moved.
Having said that MIKs plans are great, a boat building lesson on their own and fully supported by the designer. MSD is not stitch and glue, altough I did the bow that way (as He knows) and have not yet bumped anything hard enough to break it.
I dont think I can break it actually.
I havent yet met the Flint on the water, I would probably come second because Ross has a sail rig for it on his website.
Last Sunday at Wivy I was coming back with a bit of a breeze on the quarter, enough to make a hiss from time to time as I just timed it right I was wondering how I could fit a polysail from a pdf racer. That is another story
The other thing to consider about these boats is that thay are about a big as you can do without dedicated trailers. Mine usually travels right way up on a box trailer, hangs out the back too far, but the trailer will sit unloaded until the rain starts to fill the boat. Then bum down. Which is why the boat is shown on the photos on MIKs blog upside down and why the gunwhales of soft Huon pine are now damaged and need glassing, referred to earlier. It was a wet weekend when he took the photos. There are photos of my wheel arrangement, it is luggable, effective and attracts looks of astonishment but wouldnt work with a boat much larger than the ones referred to in this thread
Bye for now,
Tom

Originally Posted by Daddles

Back to Ross' Flint (I'm limited for posting time which is why this discussion is stretching out over days).

So the Flint's hull was designed to handled choppy water. Am I correct in imagining that it's the shape of the front end of the boat that gives it this ability?

What do you need to look for to get stability (tracking, not rocking and rolling) in windy conditions?

Richard

Just bumping this question, fearing that it wasn't answered through getting lost among later posts.

Richard

Richard,

I work on getting adequate rocker so that the ends are just at, or slightly above, the waterline - but make sure that there is plenty of lateral plane at the bow (sharp, fine entry) and stern (prominent skeg).

The bow, in particular, only works as lateral plane when the boat is working through a chop, and it does not contribute much to displacement. From a theoretical point-of-view, that is bad, as it means extra wetted surface to cause drag, and a lower prismatic coefficient. However, in flat water the bow is hardly immersed and doesn't add to the wetted surface, and when it does get choppy and the bow cuts through the water, it adds more through making the boat track better than it takes away through added surface area. There is nothing harder than rowing asymmetrically in order to keep a boat which has poor directional stability on track.

The Whitehall-style of boat is characterised by a deep sharp bow, and a dead straight keel with no rocker. I suspect that the keel shape evolved for reasons other than hydrodynamics and handling, and I suspect Whitehall types of being likely to overwhelm the steering ability of a single oarsperson - especially downwind or in a quartering sea. I also think that the lack of rocker may make such boats tender and unpredictable in a certain length of wave, where the stern and the bow are supported by successive wave crests, and the mid-section is lifted somewhat.

My feelings about a sharp entry and lots of rocker are supported if you look at a number of Phil Bolger's superb rowing designs such as Defender, Victoria, Dolphin, Spur II. Also, take a good look at the lines of an Australian Surfboat.

Lastly, in the case of a hard-chined design, I believe that the chine-line in body plan view (i.e. the sectional view) is of critical importance to tracking and resistance, but I'm not going to talk about that here (not enough time by half).

Before you give too much credence to what I say, remember that everything I've said is just the opinion of one person, and is based mostly on intuition.

Ross Lillistone