I'm a new catamaran sailor. I just got a wave and just tried it in the sea. I have a problem when tacking, it always get in irons. does any one have this problem? please help me. 
I have a jib kit installed and 3 persons on board.
The Wave tacks very easily, even in its normal configuration without the jib.
But if you have been sailing monohulls before, you may be throwing the tiller over too fast. With a monohull you have one hull, obviously, and usually a daggerboard or centerboard in the center of the boat for it to pivot on when it turns.
The Wave has two hulls and no daggerboards. It cannot pivot. It likes to go straight. So when you tack, instead of doing a kind of right-angle turn as you can with a monohull, you have to steer it through a curved turn. You start the turn gently and then steadily increase the pressure on the tiller as the boat goes through the turn.
Of course, there are many other factors. I don't know what your sea state is. If you have short-sequence, steep waves, that is always a problem for tacking, and you have to time your tack so you start the tack as you are coming up a wave and turning at the top so the next wave will help to turn you onto the new tack, rather than pushing you back onto the old tack.
And if you have a new Hobie Wave, you may have the new rudder system, which is more difficult to tack because it has shorter rudder arms than the original Waves and the arms are not angled inward.
And, then, of course, there is the matter of proper weight distribution when going through a tack. If you have three people on the boat and they all go to the other side of the boat at the beginning of the tack, the boat is going to want to stay on the same tack and will probably go into irons even if you do everything else right.
If you are tacking from beam reach to beam reach, make sure you sheet in the main as you head up into the tack, but you will need to ease it after passing head-to-wind or the boat will hang up and not want to head back down.
thankyou very much for your suggestions. I'll try again 
Cats will not tack from a reach at all. First rule of a good tack is you must be sailing close hauled with the main tight.
As Mary said steer up with steadily increasing pressure on the helm.
As the boat goes through the eye of the wind, ease the mainsheet a foot or so until she is on the new heading, then switch sides and sheet in.
If the sea is flat, you need not let out too much mainsheet when easing, but in heavy winds and seas more sheet may have to be eased.
Rick