Surfing Waves

I have just come back from Mexico. It was the first time I have been surfing without a wetsuit. I have learned why people use rashguards/t-shirts and long shorts the hard way. I got a rash on my chest after the first day and knees and thighs after the 3rd day

I have noticed guys at the beach were wearing below-knee and mid-calf long boardshorts. I have decided to get one of those as well.
I went to Surfdome and got a few pairs of the longest ones I could find to try them on at home.

These are supposed to be 22'but they are still only knee-length on my legs (and when I bend my knees the knees are exposed):


And these are 21' and only knee-long as well:


They all feel too short to protect my knees. I am 185cm high.

What is the correct boardshorts length? Are the ones from the photos too short? Where can I get longer ones? Thanks!

Those are waaaay too long....you'll look like a kook!!!

Your knees shouldn't have to be bend that much like in the 3rd photo when you pop up. ( well maybe, if you're not on a long(er) board ). Any longer and your knee will "catch" the leg opening and stall you just a microsecond. Right at the knee 22" looks way long enough. If you have to, try wearing a just below the knee type compression inner shorts ( we have them in Japan, not sure if they have them where you live). I use them when I go back to Hawaii after surfing in a wetsuit all year in Japan. My knees get raw too.

I think you should search on the term "rashguard pants" or "dive pants" instead of boardshorts. You'll probably have better luck.