On the 18th hole of his second round Rory McIlroy’s tee shot stopped just a yard from the lake in a difficult lie inside the margin of a water hazard, but 228 yards from the hole.
Instead of taking relief, by dropping outside of the hazard under penalty of one stroke (Rule 26-1), he chose to play the ball as it lay within the hazard. His (over) ambitious attempt to reach the green in two came up short and his ball splashed into the water. Rory obviously was familiar with Rule 26-2, as he walked to the point where his ball had last crossed the margin of the hazard before he had played from within the hazard into the water. Dropping within two club-lengths of this reference point gave him a shot of around 250 yards to the hole from a fairway lie and he made no mistake this time, landing his ball to around 15 feet. He missed the par putt and signed for a bogey 6.
The relevant point here is that Rule 26-2 affords players the option of, under penalty of one stroke; choose any of the 3 relief options they had before making that stroke. The player could drop a ball at the place from where their last stroke was made from outside the hazard (Rule 26-1a), or if it was a lateral water hazard, could drop a ball within two club-lengths of where their original ball last crossed the margin of the hazard, Rule 26-1c, which was the option that Rory took.