The "Jason" (Ιάσων) or Island Class LST was designed by Hellenic Navy and Athens University/Naval Studies in mid 1980's to replace WW2 and 1950's era LSTs. Main requirements for the new LSTs were to be capable of transfer up to 22 MBTs or APCs, IFVS, military trucks etc in all sea conditions of Aegean, Ionian or East Mediterranean plus 280-350 fully armed men. Another requirement was to be capable of mine laying. Nine ships built in two batches from 1987-1990 and 1991-1994, all identical. These are real ships of Hellenic Navy (L173 to L177), but in my AU world more built with small changes. Most significant change from real world is that all 9 ships were modernized in with new Combat Management System, received 2 SADRAL launchers, Oerlikon 35mm were modernized with AHEAD ammunition , new Fire Control System Sea Arrow Mk.3 MR and IR scope was fitted to their twin 20mm Oerlikon cannons. The 20mm cannons will soon be replaced by 30mm Remote Control Stations with Nexter M791 cannon. They are also known as "Samos" Class, because L174 Samos was the first unit commissioned into the RHN. That ship in real world is the lead ship of is class.
Type : Landing Ship
Classification : Landing Ship Tank
Shipyard : Hellenic Shipyards, Elefsis & Perama
Built : 1987-1994
Planned : 9
Built : 9
Active (2021) : 9
Ships in Class
L171 Crete
L172 Syros
L173 Chios
L174 Samos
L175 Ikaria
L176 Lesvos
L177 Rhodes
L178 Limnos
L179 Kos
General Specifications
Displacement : full load 4,930 tn, empty 2,770 tn
LOA : 380 ft 6 ft (116 m)
Beam (max) : 50 ft 2 in (15.3 m)
Draught (hull) : 15 ft 1 in ft (4.6m at stern at full load)
Propulsion : Twin Wartsila Nohab 16V25 diesel, 10,000 hp total
Screws : 2, variable pitch
Max Speed : 17 kn, service speed 14-16 kn
Range : 4,700 nm / 16 kn
Complement : 116-120 (plus 280-350 men)
Armament
1 X OTO Melara 76/62 76mm
2 X 2 X 35 mm Oerlikon GDM-A mod (AHEAD capable)
2 X Oerlikon 20/70 20mm
2 x SADRAL (6 Mistral missiles each0
1 X Mk25 GMLS, 24 missiles
2 C CM-127 chaff launchers
Aviation capabilities : Helipad for one medium helicopter up to 10 tn
Boats & landing craft carried : 4 X Motomarine LCVP-36F (originally), 4 X Watercat M12 (after MLU) of which one armed with 120mm NEMO mortar
The Watercat M12 was built under license in HLK, being its largest user with more than 100 units in service by RHN/Landing Ships Command.
I am sure that the Watercat M12 can be fitted on these LSTs, deck space is enough with minimal modifications. Davits and crane also need upgrades for lifting more weight and new beds for the M12 are also need to replace the ones for the Motomarine LCVP 36F. It also plausible for Watercat to modify the M12 for carrying in davits.