Will spend 181 days in USA during 2017 divided between two separate visits. One lasted Jan 5 - May 11 and the next will be Nov 8 until Dec 31 2017. In total this will be 181 days in the calendar year. Cruising means my arrival will be Nov 8. Will this be ok?
The "total" number of days in a calendar year that you are in the US has no significance. Each admission is separate.
When you next seek entry on B2, you will normally be admitted for 6 months. However, the officer can decide to give you a shorter period of admission or even deny you entry altogether, if he feels like it.