Where your supply pipe runs on the island decides how straightforward a repair is going to be.
Elevated houses are the easy case
Where pipework runs under a raised house in open air, a leak is usually visible, reachable and repairable in one visit. No slab to break, no walls to open. That is one thing about island building that genuinely works in your favor.
Villas are the harder case
In a multi-unit building the supply runs inside walls and between floors, sometimes serving more than one home. Finding a leak precisely matters far more, because opening the wrong wall in a finished villa is expensive and may not even be your wall.
Insulation and pipe supports
Under an elevated house, insulation degrades in sun and salt air, and metal pipe hangers corrode until a line sags and strains its joints. Both are small, inexpensive things to put right and both cause leaks if left.
The service line
If pressure has dropped throughout, the line from the meter may be the problem. Island lots are generally compact, which keeps that work contained.