Thanks all for the coments!!!
My english is not so well but Im going to try to explain some things.
About the t-shirts: In Argentina we have a Astronomy forum
www.espacioprofundo.com.ar and there are several groups around the country, one of them called "Astronomical Cuyum Brotherhood" they hosted the star party and gift shirts with the logo of his group, that is why we are all with the same shirt. Here is few more pictures and one where we are all together.
We are also distributors for several brands of telescopes across the country, including Ioptron, that is why the quantity of Minitowers
P.S.: The water was really cold!!!!
Cheers!!