This time of year there are always deadheads on Delta waterways, especially after storms. Some can be hanging around well into the spring season. Be careful out there, keep a very sharp eye out and reduce speed if needed. Night travel this time of year is a gamble. When you spot something in the water remember that you only see a small part of the actual hazard: just like an iceberg. Some of the fully waterlogged deadheads are actually suspended just under the surface and you may never see them at all.
On the plus side, winter brings unparalleled stillness to the Delta. Dry days with no wind can be especially nice.