New daysailor/racing Trimaran designs by Motive

It's certainly an interesting approach minimum rocker and a quite deeply immersed transom. Maybe trying to keep a high fineness ratio while providing adequate displacement till the main hull transom lifts free?

 

Gooday Doug & Corley. Thanks for posting those great pics - Corley. Fabulous finish for sure - lots of work to get anything to look that good. Sure puts 99% of all the other multihulls to shame - nice presentation - 100 out of 10 - at least.

Doug - like you - I'll be interested to see how it goes & the reasons behind - why all 3 hulls are in the water. Furthremore I'd be interested to know why the 'float' hulls aren't canted out ??? - - also why the beams are so low ??? - - I'm sure they will 'plow the paddock' in any slop - such as we have in many Australian sailing venues. Can't figure why they aren't curved & at least 300 mm higher.

Blinken nice boat regardless - - wish I had the money to send them an order.
ciao, james

 

There does seem to be some cant in the float hulls as you can see in the attached picture there are no front on photos so hard to judge how much. With the flat beams and large rig I'd imagine it will fly the main hull at pretty small angles of heel maybe why they are not concerned so much about beam clearance.

 

Motive 25

Found on SA(look at the twist and/or the bow down attitude of the windward ama! Looks like the Oracle 17 Twister):
http://www.youtube.com/watch?v=ngV3iM8TvyQ&feature=player_embedded

 

I'm not sure I saw any twist.
Was it just the natural pitch from a boat with the cut back bows?
You need to see the windward and leeward hulls to judge twist. Or a view from behind when they are actually under load, not tacking.

Would the windward hull slam in waves since there is no clearance at rest?
I wonder about the outbd Ama ends also. Since they are below the gunnel I assume they will really pound when going thru waves. The "modern" bows are suppose to punch thru waves rather than ride up, correct? (I see that Silver Raven asked the same question earlier - still a good question.)
Something about the flat beams looks very old fashioned. Easier to build though.

 

Motive 25

============
I think it is clear that the bow and stern of the main hull are very close to the surface whereas the bow of the windward ama is waaay lower than the stern of the ama: the ama windward ama is very pitched down. It is definitely twisted, in my opinion. I don't necessarily think twist is bad. But what is bad, again, in my opinion, is having all three hulls in the water when the thing tacks.

 

lt looks to me like the crew are too far forward, on such a light boat crew weight trim is important and to my eye they should be further aft. It's hard to say whether we are seeing platform twist or the boat pitching nose down they do seem to be going fast though. Would have to see a tack to comment on the three hulls immersed while tacking question but we do see part of a tack and it doesn't look too slow.

 

Motive have released a press release on the sea trial video.

http://motivetrimarans.blogspot.com.au/

 

The video looked good. All 16 seconds.
Why would you make a wave piercing shape on all hulls - then point out the "high volume" ama bow?
If we could see another 16 seconds perhaps we could see a reason for the shape.

Looks like a great boat, but I always thought that marketing statements should have some consistency. Can they really be saying that on a $30K boat they would not put a traveler stock? Strange penny pinching.

 

I agree it seems like a strange area to cut costs when the boat is a very expensive item and you would certainly have better sail shape control with a traveller. I suppose if you have enough money to buy the boat a retrofit of better equipment would not be beyond your means but it would take you out of the one design element if you wanted to race other Motive 25's. Ok just reread the release properly they do have a bolt on traveller option.

 

They have put up some new photos over at the Motive Trimarans blog of the screecher unfurled and the boat with the main hull skimming, looks good and the float does not look overly immersed.

http://www.motivetrimarans.blogspot.com.au/

 

------------------------
Did you see the water on the lee bow? Looks a bit draggy. They seem to have a small chine or ridge that I would suppose is there to break off the water-not working or just a quirk?
UPDATE- theres a video on the page which shows how the water sorta "clings" to the lee bow.

 

Not sure maybe one of our hydrodynamics people can comment. It used to be pretty common to see water "climbing" a plumb bow and blowing back over a multi's hull. I think it was Bob Oram who noted that reverse bows had to be very fine to shed the water easily and if they had more volume the water tended to "stick" and blow back over the boat.

 

-----------------
I've seen several reverse bow boats designed with a ridge or mini spray rail forward to cause that spray to detach without, theoretically, causing too much drag when the whole bow submerges.

 

A new video of the Motive 25r in action but once again only short so cant take too much away from it. The boat is still in development and they mention they have changed the location of the waterstays to a higher point and switched from lashings to turnbuckles on the waterstays with beneficial results. They mention that new rudders are also in development. They have also decreased the overall beam of the boat perhaps to get the main hull flying sooner.

http://vimeo.com/60300499#