Ok so I did a search for this topic and I found some good information. I could be wrong but I think my situation is a little different than what I have seen. I don't get calf cramps every time I dive, but instead every 3 or 4 dives. The interesting thing is that I will get these cramps in the middle of the night. They are really painful and cause me to limp for a good half hour after I get them. I have tried the potassium and hydration but they don't seem to help.
So my question is, does anyone have the same problem and have you found anything that helps?
I used to get cramps in the middle of the night. For other reasons I started taking multi-vitamins, deep sea fish oils (Salmon usually), drinking many cups of room temperature water every day and eating more things rich in potassium. Bananas aren't actually the richest in potassium. You might want to google "potassium rich foods" and find some lists. I'm eating a lot more cantalope but you can also do papaya, tomatoes, lima beans, plantains (good dried and served as chips) or oat bran. Most these will give you more potassium then a banana.
Additionally, avoid diuretics. Things like coffee, tea, etc. will flush water from your system. Hydrating means WATER not pop or other sugary drinks. Your body will absorb room temperature water more readily then cold water.
You might also want to talk to your doctor. Dehydration can be a sign of kidney problems or diabetes.
The suggestions of using split fins is also a good one. Before I corrected my diet, I switched from blades to split fins. It totally eliminated the cramps during diving. Makes it easier to keep up with the younger divers as well.