And there was no need for planning for close air support, there was no need to plan for armoured support, there was no real need to plan for artillery support in an era before time-fused explosive shells (these were for period mortars IIRC) In fact - I can't see there was any need for a "doctrine" - all they were doing then was what ships' captains had always been doing since Drake plodded across the Isthmus of Panama!
My point is that there wasn't a need...in the eyes of the Admiralty
...for a new "doctrine". The Royal Navy - however it was comprised
- had always
mounted amphibious operations in the rowboat centuries. Remember, in the Elizabethan age, commanders like "Captain-General" Drake even had a dual sea/land rank given to them, so that they could command at sea AND ashore!
And nothing changed for the RN until the technology changed
If anything...the REAL changes in amphibious technology was on the OTHER side...take a look at a good study of Napoleon's
preparations for invading the UK
1803-05, including ordering the production of hundreds of small, shallow-draught, low-freeboard vessels up and down the coasts of France and the Low Countries - optimized for English river estuaries and river mouths...
Whereas the British visibly kept on
doing what they'd been doing for centuries - landing troops/marines from ships' boats as and when necessary.
I would further venture that there was actually no lesson to
be learned from the Napoleonic period as far as the Royal Navy was concerned
Gibraltar, and all those Carribean islands, didn't they?
As far as Their Lordships would have been concerned - the "Carry On" level of amphibious action, rowing Marines and soldiers ashore in ships' boats...worked
And there was NO body as conservative in the face of change as the Admiralty!