All of the Lookout Posts (LOP's) were used by the "Coast Watching Service", an unarmed (and mostly volunteer) branch of the Defence Forces.

The remit was to watch for and track belligerent shipping and aircraft (both Axis and Allied), also any signs of landings, shipwrecks, survivors, landings etc.and report to Military Intelligence (G2), normally by the nearest telephone!

Most volunteers were locals (fishermen especially), as they would know what was "out of the ordinary".

They were organised into the 4 Military Commands:
Eastern (District 1)
Curragh (Districts 2 & 3)
Southern (Districts 4,5,6,7,8 &9)
Western (Districts 10,11,12,13,14,15,16,17 & 18)

In total 82 lookout posts around the Irish coast.

The Eastern Command is the bit you are interested in......

The Eastern LOP's (built 1939-42) were:

1 Ballagan Point
2 Dunany Point
3 Clogher  Head
4 Cardys Rock (official name!)
5 Rush
6 Howth Head
7 Dalkey (in Sorrento Park)
8 Bray Head
9 Wicklow Head
10 Kilmichael Point

(one was planned for Skerries in 1939, but never built)

Now here's the good bit...............

According to Military Archives (Cathal Brugha Barracks), this is (an
incomplete) list of personnel that served at:

Eastern Command - District 1 - Post 4 (Cardys Rock)

Corporals: - S.Carr, D.Duffy
Volunteers: - John Carr, E. Clarke, K. Connors, George Harpur, L. Howley, S.
Hughes, J. Kelly,
J. McMahon, R. Robinson, K. Saul, F. Thompson, H. Tuite.

Info from Michael Kennedys book - "Guarding Neutral Ireland"

Regards;