Why Warspite's floatplane attack at Narvik was exceptional

What success by a capital ship or cruiser's own aircraft came closest to Warspite's Swordfish sinking a submarine at Narvik?

No comparable example is recalled; Warspite's attack combined clear, shallow water with an exceptionally accurate strike.

Warspite's Swordfish found the submarine at Narvik in unusually favourable conditions. Clear, shallow water exposed the target and limited its ability to evade. An exceptionally accurate drop placed the weapons close enough to destroy it in one attack. Other capital-ship and cruiser floatplanes performed useful missions, but no comparably successful attack is recalled.