The problem in G4VJC's query is that the electrical contractor is speccing the fire alarm system rather than the building design team. It may or it may not warrant a full alarm and detection system to L1 but that decision should be made based upon the fire safety design strategy for the building.
Based on leisure centres and swimming pools I have encountered on the past, including those with tiered seating for viewing competitions I cannot think of any in which I would have specified detection in the immediate pool area itself. It may be appropriate to specify an L1 system with a variation omitting the pool area- or it may be better to take a look at the fire risk, life risk, building construction, fire safety strategy, how the building is used and any needs for property protection and base the spec of the system on the outcome.
73s.
(--./....-/-..-/-/-.-)