The whole thing's cruel Mike, it really is. I suspected from your fishing post when you said he had "the summer off his chemo" that there was more to the story and it appears there certainly is. Your father may not have shared it, but I'm betting he knew more than he's shared with you and just wanted to get out and enjoy that day on the water. It's an unfortunate road, with a father, that I've been down to the very end and I wish you all well in the journey. Enjoy every minute you can Mike, do what you need to do to keep him comfortable and help him get through this latest set back. Hopefully throw in a few more fishing trips. I didn't get that opportunity with my father, as we'd just started up our business 6 hours from home and I was either in the plant, or working elsewhere, basically 24 hours per day. I was 23 and invincible and have regretted to this day that I didn't take the whole thing a tad more seriously, or that I could have taken it more seriously.
If you need to chat send me a PM.