The Saltry is a must do event if you visit Homer. It's a 45 minute boat ride on the Danny J to a small island called Halibut Cove. Halibut Cove is an artist community with a few galleries and an extensive board walk that goes around the public part of the island.
You take the Danny J boat across at 5pm. Dinner is at 6 and 7:30. Do the 7:30 dinner and walk around the island before dinner (good exercise, work up your appetite). Then, settle in for an awesome dinner.
To make reservations, you need to book the trip through Central Charters at 907-235-7847. You can usual do this a day in advance - but they do have limited (about 25 people) seating.