There are a lot of world records out there for swimming. There are more than 20 different swimming events. You have to be more specific for what time you want.
Hampshire
The sailfish is the fastest swimming ´thing´on earth. It can reach speeds of 120 kph.
I have found that the fast skins are the fastest.
The most popular and fastest freestyle stroke in swimming is the front crawl.
squids.....
dolphin
The dolphin
The three fastest in order are California, Illinois, and Texas.
Where have you been? Michael Phelps.
It is the fastest.
They are the fastest swimming sharks
The Common dolphin is generally the fastest swimmer of the dolphin family.