Cape Finisterre affected Napoleon's invasion plan because the battle disrupted Villeneuve's movement. Calder's fifteen ships of the line faced twenty Franco-Spanish ships, captured San Rafael and Firme, and inflicted roughly three times the casualties they suffered during a confused action. Calder broke off as light failed and did not renew the engagement on the following days, turning a real tactical success into a public and professional controversy. In 1805, a good result could still look inadequate if it left the enemy fleet able to move.
Chapter ยท 39:26-46:17
Cape Finisterre's success and missed renewal
The Cape Finisterre account balances Calder's real tactical result against his failure to renew battle after the first day's confused action.