There's very little wind at night in the Summer usually. Port Townsend can be a bear at night and every time I've sailed there the weather was up. The brightness of the laptop screen is gonna KILL your night vision, trust me on this. I'd sail straight through but remember to talk to VTS and monitor 13 on your VHF. If it has scanning, set 5A, 13, 15 and 16. Ride the ebb through the Admiralty Inlet as the currents can run 6 knots. Check out bis_portal.apl.washington.edu for currents if ya don't have a tidal atlas. Avoid Cattle Pass at night unless you are very familiar with it, lotsa rocks and rips there. Don't get run over by the big boys and be prepared for fog to the west of Whidbey, especially near Deception Pass and abreast of WNAS. Depending on your proposed itinerary, I can go deeper with suggestions. I'd have a handheld GPS with charts loaded as a backup at the very least. Listen the above post too.