Join Date: Oct 2011
Location: New England
Thanked 8 Times in 8 Posts
Rep Power: 5
Re: Irwin 10/4 centerboard info
Unless you luck into someone here who knows, try googling "irwin owners", there are several groups and forums and you are more likely to get a knowledgeable response.
Here is the brochure for the 10/4 which describes the centerboards as "hand laid-up fiberglass and lead ballast", so it is ballasted.
Irwin 10/4 Sailboat: The Sailing Sloop Orion