Nelo Viper 55 Ski Issue

Cheers from Spain! This is Luis, a new and proud member of your comunity. Thank you so much for letting me to be part of it.

I'm quite new in paddling/kayaking. I had for five years a short fiber-glass kayak and two months ago I got an used Nelo Viper 55 Ski to discover the surfski world.
Honestly, I'm glad with the change. But there is a thing that does not allow to have a fully pleasant experience: I have a leak in the hull and it's quite significant (1 liter in one hour in flat waters). The leak is not structural, since the boat has never been damaged, and it is pretty good condition. It has been under yearly maintenance in the Nelo factory (PT) so far.
I think that the water comes into the hull through the rudder, since I can see water draining through the hole when I hang the surfski. I asked the previous owner and several expert paddlers, and they told me that this can be considered "normal". Despite this can be true or not, I'd ask your advice to minimize or repair this issue.
Thank you so much!

Is this the Viper 55 Kayak?  If so I have one and there's no leakage, the only water that gets is from splash from paddling and it is not nearly that much.

If it is a ski, is there a bailer?  That could cause leakage if the seal isn't good anymore.

If there is no bailer then you probably need a better seal on your rudder shaft, like a rubber washer.  The factory should be able to sort that out or instruct you how to do that.

-- Andrew

Welcome Luis!

No, that is definitely not "normal"! 

What sometimes happens if the ski has been dropped onto the rudder or if the rudder hit something hard in the water, is that the rudder shaft partially or wholly detaches from the hull, allowing water in. 

What you can do to confirm that the problem is in that area, is to blow into the hull to raise the pressure - you may be able to hear the air escaping or if you wet the area with soapy water, you'll see bubbles forming where the leak is.  You can check the fittings in the cockpit too - sometimes leaks develop where screws fasten rails to the hull, or where the rudder lines come through the hull.

But no, although it's not uncommon for water to get into the hull, it shouldn't be considered normal - especially not as much as a litre!

Thank you Andrew & Rob for your kind answers

One thing that I forgot to say is that as part of the yearly maintenance the boat passed a water tightness test. 
I'll check both rudder and bailer to see if the problem comes from there. I also noticed that some bolts of the footrest rails are loosen, but I don't think that it can be the cause since I've paddled only in flat waters so far. I also got advised to introduce some coloured water into the hull to detect the leakage more easily.
I'll try to install some rubber washers in the rudder and will see if I can install a new deBrito bailer since my current bailer has no door.

Cheers!

Hi Luis,
I'm also a happy owner of a viperski since a couple of years. I really love the boat! In the beginning I faced the same problem as you and it took me some time to find out, where the water gets in. Finally I found and repaired it (not too nice, I know). Check the picture!
In the beginning the crack was very small! It increased over time. Today my boat has a second crack exactly on the other side, which you wouldn't recognize as a crack. But my boat got a hatch in the back, so I can look inside. And when I come back from the paddling and I look inside, I can see the drops of water running down exactly from the joint.
Not that good!
Have fun with your viperski! It's great anyway
mirko

Thank you for your advice Mirko!
I'll examine in depth if the joints are properly sealed and double check if there is any hidden crack.
Cheers!