Continuing obstruction (RRS 18.5) question

Here's the scenario:

Boat W is to windward of boat L approaching the starting line on a close 
reach with her boom outboard of the gunwales in order to slow down. 
Boat M comes up from clear astern of boat W and tries to go in between 
boat W and boat L.  At the moment the overlap begins, there is enough 
space for M to pass between the hulls of boat W and L, but not enough 
space for her to pass between W's boom and L.  Is M entitled to room here?

IOW, does "room" as cited in 18.5 include only the hulls or is it 
"equipment in normal position"?  Seems to me it would be the latter, but 
I can't find an explicit cite of "equipment in normal position" in the 
definition of room

Note: W is not sailing backwards by backing a sail.

For reference, here's 18.5

18.5 Passing a Continuing Obstruction
While boats are passing a continuing obstruction, rules 18.2(b) and
18.2(c) do not apply. A boat clear astern that obtains an inside overlap
is entitled to room to pass between the other boat and the obstruction
only if at the moment the overlap begins there is room to do so. If 
there is not, she is not entitled to room and shall keep clear.

Here's the definition of Room: The space a boat needs in the existing 
conditions while manoeuvring promptly in a seamanlike way.

Thanks.

//Walt