X0303 4 2009-08-19 0 0001372020 Great Lakes Dredge & Dock CORP GLDD 0001246240 GRISSOM DOUGLAS C GREAT LAKES DREDGE & DOCK CORPORATION 2122 YORK ROAD OAKBROOK IL 60523 1 0 0 0 Common Stock 2009-08-19 4 S 0 14257572 5.49 D 0 I See Footnote Madison Dearborn Capital Partners IV, L.P. ("MDCP") was the record owner of the 14,257,572 shares sold as set forth herein. The shares held by MDCP may have been deemed to be beneficially owned by Madison Dearborn Partners IV, L.P. ("MDP"), the sole general partner of MDCP. Mr. Grissom is a managing director of the general partner of MDP. Mr. Grissom expressly disclaims beneficial ownership of the shares owned by MDCP, except to the extent of his pecuniary interest. /s/ Douglas C. Grissom 2009-08-21