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PostPosted: Thu Apr 28, 2011 1:17 am 
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Joined: Wed Feb 02, 2011 11:26 pm
Posts: 59
Guys,

we are based in Subic bay / Philippines and we got the Oasis 2011 model last December. Since then we had so much fun with this awesome boat, on the first ride I couldn't believe the speed you can achieve with the mirage drive. As it probably goes for most of us, after getting used to kayak we wanted to upgrade our "fun machine" so we bought additional stuff such as fish finder, rod holders and sail kit.

Am sailing the Oasis with the normal sail kit now since two weeks and - again - couldn't believe how easy it is (hey - it even goes pretty much upwind) and how you can increase the range with this tiny little sail... amazing.

Now I am wondering if it would be possible to upgrade the Oasis with AI upgrade kit. (the idea is to use a bigger sail with the amas to get some more speed and range).

I assume this should be - theoretically - possible. The Oasis and the AI are almost similar in size and probably there is a way to drill some holes in the hull to fix the amas? I figure there may be a problem with the AI mast (doesn't fit in the Oasis sail holder) but probably there is a way to make some adjustments.

The fact that you cannot use a draggerboard in the Oasis shouldn't be a big deal (I guess?) because you would have the amas to stabilize the boat.

What I really don't know is if the AI sail is to "big" to fit in the Oasis, the mast would be in between the two seats and am not sure if there is enough room between the mast and the stern to properly fix the AI sail?

What do you think? Possible or crazy idea?

peace
Serbi


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PostPosted: Thu Apr 28, 2011 11:52 am 
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Joined: Sun Aug 12, 2007 5:17 pm
Posts: 519
Location: Auckland NZ
I do not believe this would be advisable, let alone possible: there would be too many problems to resolve which would make the "project" infeasible IMO.

One thing that has been done though is to rig an Oasis as a schooner (i.e. 2 masts) which is/was a very effective way of doubling the sail area. I say "is/was" because the only Oasis model I have seen this done on was the earlier version (the one with a round black hatch in the front of the forward cockpit) and I am not sure if/how it would be achievable on the latest model with the lift-up lid hatch. The modification involved using the screw holes for that forward hatch to mount an additional mastbase made with strong stainless rod bent to various shapes & welded together (there are posts elsewhere showing the mod).

I think there is an option which might well prove effective on the 2011 Oasis, however: this option is to fly a jib in addition to the mainsail. I do this on my Adventure and it works very well (at the expense of additional complexity) in light airs - I think it would be a pretty good alternative on the Oasis because of the extra ballast to counteract the greater force of the wind in 2 sails (I have been planning to trial the system on my Outfitter but have just never got round to it yet).

I have posted elsewhere on the mods I made to achieve this (which were minimal) but basically what I did was:

Firstly stay the mast to support the extra canvas. The small mast simply is not stiff enough to support both main and jib: it bends so easily that both sails lose all their shape and most of their drive - ther effect would be even worse on the Oasis where the sails would be trying to push a much larger, heavier boat. Once stayed, however, the mast is perfectly well able to support the main and jib and very good sail shape can be achieved on all points of sail which means that the up-wind (as well as downwind) performance of the sails is excellent. I used very small diameter spectra for my stays and attached them to positions on my boat where Hobie had provided the screw in mouldings for installing their black padeye/cleat/cord-attachment fittings. I used 2 running backstays and a forestay (in fact the backstays go up to the top of the mast; through a couple of blocks tied up there and then down the front of the mast as the - double - forestay onto the end of which I have tied a micro snap shackle to attach to the head of the jib).

The second thing I did was to set the jib "flying" using a halyard and a downhaul. This means that the whole system can be set up and taken down from the cockpit whilst at sea. I use a jib from a Topper sailboat. I believe it is a ~1.8sqm sail so it effectively doubles the ~2.0sqm of the standard Hobie mainsail. I believe that other larger jibs would also work.

The third thing I did was to use a circular sheet for the jib rather than two separate sheets - this was so that I would never lose the jib sheet and be unable to recover it from the cockpit. I also used a couple of very small cleats as "sheet winches" - rather than drilling holes I tied these to the boat (actually to the seat strap fittings.

And that's about it really - I think I drilled 2 holes in the foredeck of the boat to take a padeye for the downhaul and everything else has been tied on. The cost of the components was very low - the major cost being the sail itself; if you made a sail (e.g. out of plastic tarp) the costs would be even smaller.

As I say, I think the system would work very well on an Oasis/Outfitter both of which really need more sail area to make sailing them more viable and rewarding.

By all means pm me if you would like me to send some photos.


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PostPosted: Thu Apr 28, 2011 11:59 am 
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Joined: Tue Dec 21, 2010 4:55 pm
Posts: 34
Location: Central Florida
I own an AI and it is definitely a ton of fun. I think the short answer to your question is no, you won't want to try to upgrade to the AI sail rig.

A couple of things to consider: The Aka support cross bars mount 5 feet apart front to back. I am pretty sure they would interfere with seating. The mounting holes for the Aka supports are 15 3/4 inches on center for the front and 21 1/4 on center for the rear. I believe you would have to fashion mounting plated to adapt them to the gunnels on the Oasis. Also, the front Aka support includes the mast support which hangs down enough that you would probably need to cut the cockpit floor to give it clearance.

Actually, the centerboard is important, not for stability, but to keep the boat from drifting sideways on all but a down wind run. On a beam reach the boat slides sideways almost as fast as it moves forward without the centerboard.

Last, but perhaps not least, the upgrade kit costs about $1,600 plus tax and shipping here in the US. Bottom line: If you want the AI set-up, sell the Oasis and buy an AI - you'll be happier in the long run.

OR - do as Stobbo suggests - sounds like a good alternative.

Sorry for the "pretty sure" and "I believe", but I don't have an Oasis here to check and this is after all just my opinion :D


Cheers!

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PostPosted: Thu Apr 28, 2011 5:37 pm 
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Joined: Thu Aug 16, 2007 2:25 pm
Posts: 2007
Location: Central Coast NSW Australia
Serbi,
What Stobbo and Intents said! :wink:
I seriously considered what you are suggesting a few years back on our old Tandem (Oasis). I even bought an AI with the view to swapping the parts over but in the end decided it was just not worth the effort. The most difficult part of this swap would be the mast step. The V-Brace/mast tube assembly would be very difficult to shoehorn in. The simplest solution at the time would have been to mount the V-brace on top of the crossbar. :roll:
Now the TI is available I see no point in this mod.
As Stobbo suggested adding an extra sail or jib will give you better performance.
Here is my post re the twin sails:
viewtopic.php?f=32&t=8454


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PostPosted: Fri Apr 29, 2011 4:28 am 
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Joined: Wed Feb 02, 2011 11:26 pm
Posts: 59
Thanks for the feedback...very much appreciated.

Seems I seriously need to look at the TI now...

Peace
Serbi


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