This is probably only of interest to those of us that insist on rowing.

The river can have a very strong 'up-river' flood flow on spring tides. Other times, at least with normal rain-fall, the incoming tide flow is weakened by the river. If the river gets depleted, then obviously the flood tide will have a greater effect.

There's very little in the way of 'slack' water.

When the ebb tide adds to a strong river flow, there can be 3 to 4 knots or more of current.

However, the wind can funnel up the river, so don't rely on a fair ebb flow to get you back to the pontoon from your mooring - in breazy conditions, it can be impossible to row against the wind. Be prepared to leave the boat on the river bank and walk back!