A British cruiser squadron at Pearl Harbor

What would happen if a British cruiser squadron were visiting Pearl Harbor during the Japanese attack?

The cruisers would be attacked too, but their radar watch and warnings might give ships in the harbor a better chance to prepare and fire back.

The visiting cruisers would not be an extra force capable of defeating the Japanese strike. The squadron would itself become a target and could suffer heavily in harbor. Its most important contribution might be procedural: British ships had a chance of maintaining an active radar watch and recognizing the incoming formation. Even if senior American command failed to respond, the cruisers could sound alarms, flash warnings, and bring nearby ships to readiness sooner.