According to Wikipedia, Banzai skydiving is a form of skydiving where the parachute is thrown out first and the jumper tries to catch up with it, put it on and then deploy. I tried searching the Guinness World Records website (don't have access to the book) and it came up blank. Is this a real sport and does Yashuhiro own the world record for Banzai Skydiving?
TLDR : Yes, he does hold the record, NO it's not a real sport.
I found this discussion from the Straight Dope forums.
They contacted Kubo directly, who said:
How are you.
Thank you for being interested in my record I do not know that other people challenged it after me (like same a way)
My record still appears in the Guinness Book of Records.
The record is not changed.
It will be difficult to change this record from now on
If a video is my thing, there is it.
It was on air by TVshow.
Thank you for a question
久保安宏 YASUHIRO KUBO
They also contacted the Guinness World Record people:
Thank you for contacting Guinness World Records.
The record for “longest banzai skydive” is indeed monitored in our database.
The existing record is held by Yasuhiro Kubo (Japan), who jumped from a plane at an altitude of 3,000 m. (9,842 ft) without a parachute and in 50 seconds hooked onto a parachute which was thrown out prior to his jump on 2 September 2000 in Davis, California, USA.
Thank you again for your interest in Guinness World Records.
There is a significative difference with the only working reference in the wikipedia article (and most of the stories about this on the net). He did not wait for 50 seconds before launching, but he caught (and deployed?) the parachute 50 seconds after the launch.
As Trupa, a former skydiver said (conversions in square brackets mine):
Skydiver's rule of thumb:
15 seconds to terminal velocity covering 1500 feet [457m] of altitude. Then at 120 mph [193kM/h] terminal velocity, 6 seconds per thousand feet [304m].
So, for 50 seconds:
50 = 15 + 35 (let's say 36 to make life easy)
= 1500 feet [457m] + 6x1000 feet [304m]
= 7500 feet [2286m]. From 10,000 [3048m] you're at 2500 feet [762m], and minimum allowed opening altitude is 2200 feet [670m].
Now the rig free-falling alone won't fall as fast as a man, so the chaser won't have to fall for 50 seconds to catch it. but given the time required to put on the harness (2 thigh straps, the shoulder straps, and 1 chest strap) let alone the time to chase & catch it, and I say you run out of time more often than not from 10000 feet [3048m]. From 14000 [4267m], maybe you have an even chance. It's still heads you die, tails you live.
The right answer to this question is yes, Yasuhiro Kubo is the Guinness World Record holder for banzai skydiving. And yes, it is a real sport. As for the first part of the question, Guinness Book of World Records Editor Craig Glenday stated that Yasuhiro Kubo is the record holder. To clear up a misunderstanding, Glenday describes the key element of Banzai skydiving is the wait, “throwing your parachute out of the door, then waiting as long as possible before jumping after it.” You have to wait. Then he says, “the longest wait yet is, incredibly, 50 seconds by Yasuhiro Kubo of Japan.” Now is it a sport? Yes it is a sport, Banzai Skydiving is an extreme sport that was started in Japan. It consist of climbing to jump altitude, 10,000ft., throwing your parachute out the door, wait 2 seconds, and then jump after it. Kubo waited 50 seconds. So the sport itself started in Japan. Skydiving by definition is a sport. So there is the right answer.