mate i would go with the 3 point harness if you really wanted to.
it also depends on what type of pots you have, if they are highly expensive $50 - $60 pots then the chances of them getting out are highly doubtful.
but howver the cheaps $10 pots, crabs can probabyl get out of, one day i chucked an old bcf pot in a local creek, when i was pulling it up watched a decent crab just go straight out of the whole .
hope i helped a bit
daniel