Crabs!!!
 

Can someone pm me the secret to defeating the crabs?

Arg those crabs!
 

I use my sword on the crabs and get the best results if I get 3 hit combos in. If I don't want a challenge, I select a crab that's by itself. Make sure you're not too close or they bite you without you landing any blows. It's really difficult if there are two crabs of a better level. In that case, when necessary I have to back away to get my health back before continuing.

Frankly, I'd much rather take on a skeleton than the crabs. I hate crabs now!

I had luck shooting the crabs on Port Royal. It sure helped me level up my pistol quickly. :)
As for those Rock Crabs, I have thought about buying grenades for them LOL.

Grenades! LOL I just may try that. I accidentally pulled my pistol yesterday and was surprised that it shot.