If you have British navy connections you may find Navy Records Online of interest. It's an expanding online archive of miscellaneous British naval records and the internet publishing arm of the Navy Records Society (est. 1893).
For £20 a year members receive access to the latest discoveries and are able to browse the online archive of charts, portraits, cartoons, logs, letters, diaries, battle plans, sketchbooks, photograph albums and videos. The society preserves significant naval records of every type.
A catalogue of the Society publications is available from the Society website. Members have access to three digital volumes as part of their annual fee.