Yes, you need to sign waivers everyday you want to go on the flowrider. There are two lines on each side and it does move rather quickly, depends on how fast you wipeout. Once you fall off, your turn is over, but feel free to get right back in line. Its still interesting to watch everyone else while you wait in line.
Just check the daily cruise paper for times when its open.
I just returned home late last night from the Freedom of the Seas.
When you first sign the waiver for the Flowrider they gave me a black wristband to wear. As long as you have the black wristband on, you do not have to resign the waiver every day, if you take it off (like I did one day), then you have to fill out the form again. Each day then has a different colored wristband, for a total of two, the black waiver one, and the color of the day.
The cruise compass will have different times listed for the boogie board and stand up surfing. Usually it was Advanced stand-up surfing 8:15-9:00am, Stand-up surfing 9-11 am and 1-3 pm, and boogie boarding 11am- 1pm and 3-6 pm.
Port days the lines were much smaller, sea days, especially near the end of the cruise were longer. Your 'ride' lasts until you fall off. My last day, it was running around 2 rides / 1/2 hour, mostly because of the longer lines and that most people could actually stay up surfing for a period of time.
The staff would help push you out, and balance you, before letting you go.
Later on in the trip they would also show you how to push yourself out, (which actually seemed easier). The trick to surfing on the flow rider, is just keep practicing.
Nov 90 NCL Skyward
Nov 91 Star Princess
Feb 06 Carnival Conquest
Feb 07 Carnival Squalor
Jan 08 Freedom of the Seas
Jan 09 Celebrity Solstice
Jan 10 Crown Princess
May 10 Navigator of the Seas-Med
Jan 11 Oasis of the Seas
May 11 Independence of the Seas-Canary Is.
May 11 Vision of the Seas-Baltic
Jan 12 Island Princess-Panama Canal
Oct 12 Oasis of the Seas-Halloween
Dec 12 Mariner of the Seas-New Years Eve
Feb 14 Independence of the Seas