I'm trying to choose my first duty station and one of the many factors in my decision is time at sea. I know no matter what that I'm going to have to spend a long time at sea but I don't want to be away from family too long. I heard that coastal riverine are never gone for too many months. What are the best and worst options for time at sea?
As already noted, all ships more or less operate on a similar deployment rotation cycle, so on average, it all looks the same.
And every deployment is basically going to be about 6 months minimum.
The only way you can avoid that is to go to a FDNF (Forward Deployed Naval Forces) ship, such as in Japan or Rota, Spain. They do not do the standard single long deployment, because they are homeported near their operating areas.
However...the tradeoff here is they are extremely busy and subject to surges. So you won't be gone for that single long duration period, but you could be constantly heading out for a month or two with only a few weeks in between to recover.
Every time North Korea sneezes, some Japan ships are likely to get extra tasking.