Penton Hook to Limehouse - first time on the river and a new boat - help!

Can you (still) actually get onto the lake at Penton Hook? I've heard mention of this many times, but not really sure hwere to find it, and if you can realloy get onto it. Isn't the "lake" landlocked, except for a non-navigable channel?...

<<someone has to ask the dumb questions. It's my turn now!>>
 
Was called 'the pit' in my day ;)

All the marina kids used to go and zoom around in their dinghies up there ! Great fun !

The entrance to the pit is right opposite the top of pier 1a ( is it still called that ) ?
 
Isn't it supposed to be a Nature Reserve -

The only known home of the Lesser-spotted-bladderwort (penton hook variety)???
 
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