The deal, for an undisclosed sum, sees former UBM divisional managing director Trevor Barratt leading the management team. Tony Tillin, who previously chaired AAC's investment in Quantum Business Media, joins as chairman.
Barratt said: "We intend to grow the company organically, drive revenues in digital media and expand by selective acquisition. We are excited to be joining the business at this stage and are very optimistic about the prospects for the future."
The acquisition follows the firm's £41.5m management buy-out from Trinity Mirror 15 months ago when it rebranded from Inside Communications. Ocean managing director Dave Moran and finance director Simon Malcolm, who led the MBO in 2006, will remain as consultants in order to complete a handover.
Moran said: "Simon and I have worked together for 10 years, successfully turning around a number of media businesses. We are delighted with the performance of Ocean Media Group, which is a high-quality business capable of continuing to demonstrate excellent levels of growth, both organically and via further acquisitions."
Ocean has three businesses: Social Housing, which includes the Chartered Institute of Social Housing annual conference; Weddings and Bridal, involving the British Bridal Exhibition and the National Wedding Shows; and Leisure & Outdoor, comprising the National Boat and Caravan Outdoor Show.
The media firm also boasts numerous trade and consumer publishing assets.