DO NOT USE SILICON!!! Worst thing you can do. It will be hard as you know what to remove, and nothing will ever stick to it again.
1. get some mineral spirits and clean the old caulk. no need to remove
the old caulk, just clean it.
2. get some acetone and reclean the caulk. It will remove any residue.
3. get a caulk tube of Dicor non-sag caulk and apply it right over the old,
and now clean caulk.
I have a 2012 283ts, and just recently did the same thing to mine. Noticed a few cracks. Cleaned it as above and applied a bead of new Dicor caulk and smoothed it down with a wet finger.