Thursday, March 13, 2014

VIKO 30S / VIKO 22S

Well, it was inevitable a post about that and I think I own you all this post. Most of us are interested in boat design and that is an interesting subject that comes from the previous site. We all know that it ended up badly and I purposely did not made it there trying to avoid confrontations but there is no reason why I would not develop it here.

So, both boats are designed by Sergio Lupoli and have obvious hull similitude. Both have nice modern hulls (the first one will always be the 22S):
The 22s, being smaller, in an attempt to provide more living space in the interior in what regards available height, has obviously a bigger freeboard. On the pictures look at the chine at the back of the hull and the height that goes from it till the top of the hull:

The two last images even if featuring boats with the same hull color are the first one from the 22S and the last one from the 30S. We can see that the difference in freeboard is particularly noticeable on the transom, that the 30S is a good looking boat and not one with a particularly high freeboard for a 30ft cruiser and that it feature sportive looks:
The Viko 22S still looks good if we consider the need of a big freeboard to allow a decent height in an interior of a 22ft boat but it is a mixed horse. It has some looks of a performance boat but the overall picture is spoiled by the obvious excessive freeboard. That is particularly true in a posterior view. On the last picture we have a 30S:
Even if the lesser freeboard of the 30s, with less windage and the weight of the crew lower on the cockpit, points to a more sportive boat, that is not the point where the two boats diverge radically, neither it is on the hull design but on the B/D ratio.

 Both boats have similar keels with different options but to simplify lets look to the more sportive one, a similarly designed torpedo keel. The B/D ratio of the 22S is 21% while the one of the 30S is 31%. This huge difference is aggravated in what regards RM provided on the 22S by a smaller draft (1.50m to 1.65m). Normally smaller cruisers have a B/D ratio bigger than bigger ones not only as a precaution against the smaller overall stability but also because the weight of the crew and load can have a bigger impact on the overall stability (the 22S only weights 1200kg).

This is what really makes those two boats radically different and while the 30S joins to the considerable form stability to a considerable RM coming from the ballast, the 20S relies mostly on the form stability and that was very clearly stated on that Yacht.de boat test were not only they found  that the sportive look of the boat did not corresponded to the sail performance as the boat had an insufficient final stability:
I did not read the boat test but I bet they found that the boat had a normal sail performance downwind or in weak winds but that upwind, in anything less then weak winds, it would have an insufficient performance, needing reefing very early and if pushed could finish on its side.

 I don't understand why the shipyard had asked the designer for a cruiser with these characteristics and I don't understand also why Segio Lupoli could not convince them otherwise. He designed small boats for Comet, some with similar looks and high freeboard (Comet 26) but contrary to the 22S with an adequate stability and a much bigger B/D ratio for a similar type of keel and draft.

Yes, a boat with a small B/D ratio can be less expensive to build since the hull has not to support the forces generated by a bigger ballast, but the option that they took on this boat looks pretty ridiculous to me and on a second thought to them since they are already working on a 21S that probably is going to substitute this boat and perhaps will join the 31S on the line of more sportive boats, aiming for performance cruising that is clearly not what the 22S was intended for.

Bottom point, after having looked at the numbers and after having a good look at the boat in Dusseldorf I sustain that the 30S is an interesting boat at a very interesting price, a boat that almost for sure will have a good sailing performance. I count with Anders to see if my opinion meets the ones of the Yacht.de testers when they test the boat and that should not take a long time to happen.

8 comments:

  1. I've tested the viko s 22 for a day and I can confirm all Paulo suspects on her stability. She also does not sail properly downwind, where it rolls unbelivably at every wave or puff of wind.
    I would define it a dangerous boat.

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  2. Thank you for your feedback :-) Now if you have the chance to sail the Viko 30 I would be very interesting to know if in that case your opinion will also match mine, I mean that it is a completely different type of boat even if they don't look that different.

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  3. I have added 250kg to the bulb on my viko22. Nowit works great!

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    1. Yes, I believe it will make a big difference.... but take care, for doing that you have to reinforce the boat structure too, otherwise you risk breaking the boat. When the boat is heeled the lateral efforts on the structure will be incomparably bigger with those added 250kg.

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  4. Barca pericolosa e non navigabile.... PERICOLOSA !!!

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  5. Hello! I was considering buying the Viko S22, but now you have got me thinking.. Is the S21 a better option? Also said it is aprox 4000 euro cheaper.. Thank you for your answers!

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    1. If the data they publish on their site is correct yes, they have bettered the boat, besides the 21 looks a lot better.

      In what regards stability both boats have the same beam and considering the version with the T shape lifting keel (more stability) we can see that the new boat has 300kg of ballast while the 22 had 250kg. It does not seem a big difference but if we consider that the 22 displaced 1200kg and the 21 only 950kg that gives for the 22 a B/D ratio of 21% and for the 21 a B/D ratio of 32%, a huge difference even considering the slightly superior draft of the 22 (1.50 to 1.40).

      Now, don't believe in the data they post on their site and try to find out if it is really accurate, at the factory. If that is the case and the numbers are those than the 21 is by far a better sailboat, since the designs are very similar, except on this point.

      Anyway like any small boat of this type the weight of the crew (that is a considerable percentage regarding the total weight of the boat) and its position will always be important to sail correctly the boat and to its performance.

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    2. Hello and thank you for your good answer!
      I have seen on Viko website that the Viko 23 also is an alternative, although is an older model. Is it a better option then the S21 or the S22 models? For me as e beginner definitely I will not buy the S22 model suspecting it can roll over quite easy..

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