Mr Simkins serves as a member of the board of directors for each individual company at The Washington Companies, a group of privately held companies active in the core industries of rail and marine transportation, mining, aviation, environmental remediation and restoration services, and heavy equipment sales and service.
Mr Simkins also previously served as a director of the Federal Reserve Bank of Minneapolis.
In addition, it is anticipated Seaspan's board will expand from eight to nine members, adding WashCo director David Sokol as a board director, according to media reports.
Gerry Wang, CEO, co-chairman and co-founder of Seaspan, commented: "We are pleased to welcome fresh perspectives and ideas from Larry, and later this month from David, as representatives from our largest shareholder and proven business leaders.
"We are encouraged by recent positive signs of a recovery in the global container shipping market, and believe that the newly constituted Board will enhance our ability to capture emerging opportunities, benefiting the company and all of our shareholders."
Kyle Washington, co-chairman and co-founder of Seaspan, commented: "On behalf of the Board, I would like to thank Graham for his many years of service and contributions to Seaspan - a company we, together with Gerry, built into the world's leading containership leasing business. We wish Graham all the best in his future endeavours and know that Seaspan is well-positioned for the future, and in good hands with our incumbent and new directors, both of whom I know and respect from our many years working together at the Washington Companies."
Hong Kong-based Seaspan has a managed fleet consisting of 114 containerships with a total capacity of over 915,000 TEU, including 11 newbuilding containerships on order. The company's operating fleet comprises 88 vessels.