lobster nets, worth it?

Hi!

I'm a recreational sailor, and I'm not really much of a fisherman.
But, I wanted to see if anyone has any advice about lobster trapping.
I anchor in 8-20' of water all the time while I'm cruising, along the
Massachusetts coast. That seems like good lobster territory, and
recreational lobster licenses are available here in MA.

The problem: traps. Too big to carry on a 30' boat. I can, though,
get a net. SOme of them are like basketball hoops, with a bottom,
others are like pyramids that close when I yank them up.

Do these things work? How often should I expect them to work? How do
I know when to yank them up?

Can anyone point me at a book that will help with this?

Thanks for the replies! If folks reply via email, I'll summarize the
best advice and post it in a week or so.