Advandreev wrote:Hello!
I am beginner in surfing and I order a custom board from Chinese company over alibaba.com
I ordered it in this sizes:
Length 7'6"
Width 23"
Tail 16,5" Nose 17"
Thickness 3"
Medium rocker
Swallowtail
Thruster Fins
What do you think about this board?
Oh dear

Custom board AliBaba and Chinese company are not the elements of a custom board
A custom board is where you have a relationship with a genuine surf company and a shaper, you discuss your style and ability with the shaper and they make you a board.
Sadly and I hate breaking bad news, you have duped yourself through lack of knowledge, a lot of the shiny new boards that appear on internet mass selling sites are made in China and are imported by the container load but people on the edge of the surfing industry out to make a quick dollar and move on.
They are often made in situations where there is poor quality control and they can be dogs.
There are quality boards made too by reputable people in the surf industry and if you buy a pop out then a good name is better.
More OH Dear 
I'm sorry to say the board you have chosen may work for you

It could be forgiving in its thickness but I somehow feel that you have just downloaded the dimensions from AliBaba without understanding what they mean in relation to your weight height and age and your lack of experience!
I'm so sorry hopefully you are young, light and not above 6ft tall and you can hit the water every day, the board will then have a chance of meeting your needs.
Hey all is not lost

Post a picture of the board.
Read around the forum, you'll find that others have taken the same path as you , but have recovered and are now learning to surf OK
