SO has a new job, will be working away?

Im 36 weeks tomorrow, and yesterday my SO told me that he's been offered a new job at sea where he will be away four days a week, and home three days a week. However, he has his own fishing boat and so would still work on those three days that he IS home. I'm not sure how I feel or how I should feel about this...? I find it tough enough being alone for a day or two while he's fishing now, so I'm not sure how I'll cope when he's away for four at a time, every week...what if he's at sea when I go in to labour? What if he misses his daughters birth?... Has anyone else been through this/similar? How did you cope? What was it like raising your baby alone part time?... I'm so worried he won't have a relationship with her and our relationship will weaken and we'll drift apart... Any comments are greatly appreciated.