Scott's alibi or anchor ... or nothing?
The waterway directly in front of you is the only way into the boat ramps that SP used to launch his 14 footer on Christmas Eve. He would have traveled left to right heading out in that open waterway between the large sections of docks. This is an active webcam. I just went out and observed it and lots of people using the park. The park paths are just yards from where SP would have boated out around to Brooks Island. Brooks Island looks like it's only a mile or so away but the waters can be rough once you get away from the breakwater devices installed near the inlet to Berkeley Marina.
In addition, I traced SP's most likely route off the freeway to the Marina. Many illegals(?)near a building supply house looking for day work, all kinds of public access businesses with front doors and windows facing the street SP would have pulled his boat down. AND, AND an ATM facing the roadway. A very busy ATM in a trendy area of revitalized Berkeley near Spenger's Grotto.
Hopefully LE has the tapes from the ATM and the sailing club. They could have been recorded over before they were analyzed, though.
It would take about 15 - 20 minutes to get to Brooks Island in a boat that size with a 15hp engine.
Yes, you would normally stay fairly close in to make that trip, it's basically a straight shot. I posted a picture I took of it on another thread.