So I had an idea that thought would be easy. I know how to use poser player and osmp's.

I went to sunset valley, took my sim to the beach, used nrass to open up build/ buy mode, took pose player and posed sim, then selected the sim use moveobjects on and realized the sim cannot move beyond the grid.

The ocean is beyond the grid. If I tell my sim to swim, they cannot pose.

I want the sim to stand and pose in the ocean water at the edge of the lot, off the grid.

How would I go about that? What am I doing wrong? Please help. I'm so frustrated.

I would have accepted defeat until I saw a creator of a pose pack released a posepack where they did it:

https://pis3update.tumblr.com/post/...sims-3-by#notes
Which means it's possible.

Do I need the Island Life expansion?

According to patch 1.55 it is an included feature that lots can be placed partially on the land/beach and in the ocean. You do not need IP but what you want to do is either add a new lot to the beach that connects with the ocean or delete the existing one and replace and rebuild any structures if desired.

Thank you Deshong, I will do and try that out. So helpful!