Swell scares you and makes you sick but depending on the period probably wont hurt you or your boat. Chop can throw you off your boat and high short period chop can damage your boat. Chop on top of swells can toss you about like a rag doll, make you sick, and trash your boat.
While your stuck in harbour google
these terms for some reading about wind
, waves, and how they are formed:
Fetch, wave, nm, chop, current
If you search for all of them at once you should find some great articles on wave theory and how to predict nasty waves. On the atlantic with winds blowing westward you can use the figures for unlimited fetch on the tables. Sidebar reading for you would be also reading how fetch, wind, and current
interact creating nasty chop under the right conditions which youd want to avoid. A set of charts
how to read the current markings is also helpful.
If your laid up may as well do some learning
. Personally i am not a fan of big waves on the water in my 26, because i mostly did lake fishing
before getting an ocean boat. So i learned all i could to be able to as best as possible predict how they form so i can avoid them if possible, or at the very least, avoid uncomfortable points of sail.