any suggestions

it's a common problem for kneelo's that use flippers. My solution was to stop using them.

some people say that magnesium tablets or bananas helps but I have never seen this backed up by medical research. see your GP.

Used to suffer when first started taking water photos, way back in the day.
Mechanics:
Try taking a break from the constant "ballerina" kick (toes extended/180degree angle). When you're waiting for a wave, try treading water with your foot at 90degrees (toes up/heels down). Don't lockout your ankles when you're kicking.
Use shorter blade fins if you are using divers fins.

Physically:
Assuming no underlying health problems...
Make sure you are properly hydrated.
S-T-R-E-T-C-H

I found Magnesium helps with cramps, and even the sip of sea water

I suffered from leg cramps surfing for a long time. This is what eventually fixed me
- stretching
- hydration
- magnesium tablets
- fewer big benders (cramped up a LOT worse after a night on the beers)

Good news Davo! froGthing! I used to get this problem during squad training. Plain water didn't help but adding Endura did, plenty of that stuff floating round the GC I'm sure. I force myself to drink at least a bottle of water before surfing and it does delay the problem. But after 2+ hrs at TOS or something, you can't just go in and have a drink from the tap. So like 50young, I drink seawater, from below the surface (avoid floaties). Salts and sugars give me stomach cramps/ bolatedness/ discomfort though and I'm not sure if there's any way to avoid that. I'm not a consistent stretcher/ yoga, but I do try and stretch my hammies before going in and while teabagging; holds the cramps off a little bit. It's probably what I should be doing you know...

Davo, perhaps no more leg over shoulder with jimmy B........ ;)

well being the fine alcohol abstaining sex free choir boy that my mother superior is so so proud of, all i can say is thanks for all the suggestions. Using magnesium and amino acids, using special brew called dutch courage to sweettalk all the sheilas- so looks flippers can stay a dolphin.
Sd i saw no glaring mistake in your goldy crowded state, mate, its called inter generational equity, regardless of what infrastructure a local governing body erects/performs (not like u anymore- many erects-many non performs.lol), if it enhances the communities social, economic or environmental value, it has to be obtained. So I dont know why you are on about things being man made or not, I seem you didnt have any problems sharing squirtas plastic doll sometimes!. lol big big time

sorry mate, as i have been active lately, as it nows seems, i have 400 emails sent to me, someone been posting on my tweeter account, just stuff to annoy me. hey least i now have photos of miranda kerr.
nm here today, beautiful swim down anchorage in shelter, water coolish but pristine. hope ur well. back to back hawksters