First - you might want to consider making an insurance claim - this would likely be covered under your boatowners policy. Probably a $500 deductable, but you will get OEM quality.
You can make one yourself out of lexan or plexiglass - use a heat gun or hair dryer to help with the bending - several good u-tube videos on that process. You can flame polish the edges after cutting or use a buffing wheel and compound - again, check utube for this as well.
Good luck!