What role does Hornblower play in Meadows' court martial in the novel, Hornblower During the Crisis?

Hornblower testifies in a way that tends to exonerate Meadows. He notes the difficult local conditions and tricky tides and currents in the area and establishes that Hotspur's proper station was in the general area of Black Rock. In response to a direct question, however, Hornblower admits he guided Hotspur into the same area nearly every other night for two years without incident.