The ease of getting in and out of the zodiac is very dependent on sea conditions - it can be tricky. I saw people fall over, more than once. In all cases, you make a "sailor's grip" (they will demonstrate this) with both arms and hands, so hands must be free. They will take your poles and give them to you once seated. The crew is great - just let them know your situation, and they will do everything they can to help. If they feel it is too rough to make a safe entry, they may not allow it, but they really do want you to experience Antarctica and will do their best.