I have a 16'boat. With the motor and trailer , the gross weight is about 1950 lbs.

I believe the 2003 CRV towing capacity is 1500 lbs.

Can modifications be made to tow my boat?

buy a bigger truck

Or a lighter boat. :iceslolan

You would have to do alot mods to make your CRV capable of towing that much. Not only would you have to beef up the suspension but you would have to get a stronger motor and drivetrain.