Spelljammer Gravity Plane

[MonsterEnvy]

Somehow the gravity between the character and ship aren’t enough to draw them together.

That is cause there is none.

 

[Sorcerers Apprentice]

Since there's air surrounding a spelljammer, you should be able to generate some forward motion by waving your arms and legs around, so with no other forces working on your body you should be able to eventually get back to the boat on your own. Experienced spelljammer crew might carry folding fans or the like to make it easier to push against the air.

If the physics of wildspace work the way as described in 2nd edition, then you might have to flap very hard to overcome the push towards the edge.