If you are an Art Gallery with an interest in seascape paintings you could be listed here (free). Also see the Marine Art Ireland Page on Facebook for news / events.
Directory of Irish Art Galleries: http://www.irishartgalleries.com
Galleries interested in Marine Art
The Russell Gallery; New Quay; Co. Clare www.russellgallery.net
Denis Collins Gallery, Wexford www.artupstairswexford.com
Greenlane Gallery, Kerry www.greenlanegallery.com
Annemarie Bourke Gallery, Limerick www.artannemarie.com