I agree that more context would indeed be helpful as individual hotels can use these terms to mean pretty much whatever they want. When researching this term, for example, you will come across a South Korean hotel that offers both “half ocean view” and “partial ocean view”, suggesting, in that case at least, some sort of difference. It could be that a “half ocean view” is available from rooms on lower floors, where the bottom half of the view from the window consists of the grounds, garden, bay, city, etc., with the ocean forming only the top half of the view (see photo here, for example: as well as a half-garden-half-ocean view veranda
http://vivasalvatore.blogspot.co.uk/2013/01/im-yours-mulia.h...Rooms on higher floors are then the ones marketed as “ocean view”, e.g. “Depending on affordability the higher sea view rooms have wonderful views, the half sea view rooms are just that”
http://www.tripadvisor.co.uk/ShowUserReviews-g189112-d119194...