Dead calm... Then a set of 5-6' rollers, every few minutes. Would have been VERY easy to get in a bad position.

It was REAL calm were I was, I felt like I was at a lake

Long period ground swell.

Long period ground swell.

explain...

Swell coming from a long ways away as opposed to a shorther period wind generated swell. A short period swell would be say 3 feet at 6 seconds while a long period would be 3' at 13 seconds. Long period means longer time between sets and more defined and powerful waves.