How about the baptism you have witnessed?

Two weeks ago I went to a fellowship in my university for the first time. In coincidence there was a baptism. The ritual went like this: the 8 persons who was going to receive the baptism kneeled in the water and the baptist (I am in China and the baptism that day was held by an American) bailed water and poured it onto the head of the receiver. I was just wondering whether it was being by the reason of limited space there. When five years ago I received the baptism I sat in the water and the baptist asked me "Do you believe that Jesus is your redeemer?". As soon as I replied "Yes" he pressed me into the water and after my whole body was submerged he pulled out from the water. The baptisms I have saw before mine and after that all go like mine. Thus I found it quite strange and confusing, yet I didn't convey my doubt to the Christians attendant.
The connotation of the "baptizw" in gthe Bible is "submerge", which means sink under the liquide. Therefore the receivers should be submerged their whole body. Although the literal explaination might have differences with the original one due to the changes of ages and dynasties, we are still able to know something from the historical fact that the baptism in the early period of church were all went to submerge the receiver's whole body. As what was written in the ACTS 9:36-39,"As they were going to along the road, they came to ome water; and the eunuch said,'Look, here is water! What is to prevent me from being baptized?'.....Philip and the eunuch, went down into the water, and Philip baptized him. When they came up out of the water...", it is quite clear that being baptized is to be submerged in the water. Some baptisms only go to pour or drop water on the head of receivers.
The determination of Baptism is to demonstrate the fact that we die and revive with the Christ, only by submerging your body can our baptism have such meaning. Man enters the zone of water as if he is died. Submerging himself is like to buried himself in the grave. To do so we buried our sin, sinful nature and the world. And to rise up from water means reviving from death and grave. All these actions embody the fact that we combine with the Christ.
The above are something that my father told me after I told him the baptism I have witnessed recently.
Do you agree with me? And how about the baptism you have witnessed?