We had booked a place at one of the marinas on the Tiber itself. At its mouth, the river (Tevere in Italian) is called the Fiamare Grande. This distinguishes it from the Fiomicino canal which cuts through the back of this cape and joins the river further inland. We have read of many boats which have wintered in the canal, but we had not been able to get a place there. Also it is very close to Fiomicino Airport, and, although we had not seen it commented on, thought that would be unpleasant.
This lighthouse is now out of use, showing how little large shipping now uses ports on this coast. There is a big ship anchorage, and some offshore platforms, in the vicinity, but inshore it's only small fishing boats and pleasure craft.
Entering the river is very straightforward in calm weather. There was a red beacon marking the channel, and we saw least depth 6.3m. The banks are lined with substantial shacks and fishing gantries, but its not an impressive riparian entrance to such a great city, more its neglected back door. Rather like London's attitude to the Thames in that respect!