First of June's pebbles

After the success of the last river of stones in January (see my first January post for details here) there's another happening this month. Actually, I've just noticed I'm a month early - perhaps I'll just keep going anyway.

Three levels above the deck,
a tarpauline flaps in the wind,
keeping the rain off instruments,
a shifting spanner, an oily rag,
and a chair pushed under
a scaffolding bench.