diff --git a/src/mame/igs/igs_m027.cpp b/src/mame/igs/igs_m027.cpp
index 83e5730ac1b..a8b9ad19969 100644
--- a/src/mame/igs/igs_m027.cpp
+++ b/src/mame/igs/igs_m027.cpp
@@ -64,6 +64,7 @@ public:
 	void init_klxyj();
 	void init_slqz3();
 	void init_fruitpar();
+	void init_oceanpar();
 	void init_amazonia();
 	void init_amazoni2();
 	void init_qlgs();
@@ -1215,6 +1216,13 @@ void igs_m027_state::init_fruitpar()
 	pgm_create_dummy_internal_arm_region();
 }
 
+void igs_m027_state::init_oceanpar()
+{
+	oceanpar_decrypt(machine());
+	//sdwx_gfx_decrypt(machine());
+	pgm_create_dummy_internal_arm_region();
+}
+
 void igs_m027_state::init_amazonia()
 {
 	amazonia_decrypt(machine());
@@ -1271,8 +1279,8 @@ GAME( 1999, qlgs,      0,        igs_mahjong, sdwx,     igs_m027_state, init_qlg
 GAME( 1999, amazonia,  0,        igs_mahjong, amazonia, igs_m027_state, init_amazonia, ROT0, "IGS", "Amazonia King (V104BR)", MACHINE_IS_SKELETON )
 GAME( 1999, amazonkp,  amazonia, igs_mahjong, amazonia, igs_m027_state, init_amazonia, ROT0, "IGS", "Amazonia King Plus (V204BR)", MACHINE_IS_SKELETON )
 GAME( 1999, fruitpar,  0,        igs_mahjong, sdwx,     igs_m027_state, init_fruitpar, ROT0, "IGS", "Fruit Paradise (V214)", MACHINE_IS_SKELETON )
-GAME( 199?, oceanpar,  0,        igs_mahjong, sdwx,     igs_m027_state, init_fruitpar, ROT0, "IGS", "Ocean Paradise (V105US)", MACHINE_IS_SKELETON )
-GAME( 199?, oceanpara, oceanpar, igs_mahjong, sdwx,     igs_m027_state, init_fruitpar, ROT0, "IGS", "Ocean Paradise (V101US)", MACHINE_IS_SKELETON )
+GAME( 1999, oceanpar,  0,        igs_mahjong, sdwx,     igs_m027_state, init_oceanpar, ROT0, "IGS", "Ocean Paradise (V105US)", MACHINE_IS_SKELETON ) // 1999 copyright in ROM
+GAME( 1999, oceanpara, oceanpar, igs_mahjong, sdwx,     igs_m027_state, init_oceanpar, ROT0, "IGS", "Ocean Paradise (V101US)", MACHINE_IS_SKELETON ) // 1999 copyright in ROM
 GAME( 2002, sdwx,      0,        igs_mahjong, sdwx,     igs_m027_state, init_sdwx,     ROT0, "IGS", "Sheng Dan Wu Xian", MACHINE_IS_SKELETON ) // aka Christmas 5 Line? (or Amazonia King II, shares roms at least?)
 GAME( 2003, amazoni2,  0,        igs_mahjong, sdwx,     igs_m027_state, init_amazoni2, ROT0, "IGS", "Amazonia King II (V202BR)", MACHINE_IS_SKELETON )
 GAME( 200?, sddz,      0,        igs_mahjong, sdwx,     igs_m027_state, init_sddz,     ROT0, "IGS", "Super Dou Di Zhu",  MACHINE_IS_SKELETON )
diff --git a/src/mame/igs/pgmcrypt.cpp b/src/mame/igs/pgmcrypt.cpp
index f13e605c61f..b52213ff6ee 100644
--- a/src/mame/igs/pgmcrypt.cpp
+++ b/src/mame/igs/pgmcrypt.cpp
@@ -1607,7 +1607,52 @@ void fruitpar_decrypt(running_machine &machine)
 	}
 }
 
-static uint8_t amazonia_tab[0x100] = {
+static const uint8_t oceanpar_tab[0x100] = {
+	0xad, 0xe8, 0xf9, 0xf2, 0x2e, 0x20, 0x6c, 0x06, 0xfe, 0xed, 0x42, 0xaf, 0x60, 0x33, 0x7e, 0xa4,
+	0x6d, 0xac, 0x09, 0x5e, 0xc0, 0x8f, 0xfb, 0xd4, 0x61, 0x61, 0x29, 0x75, 0xf4, 0x1b, 0xef, 0x67,
+	0x23, 0x7d, 0x3f, 0xff, 0x48, 0xb2, 0xea, 0x81, 0x5f, 0x25, 0x2e, 0x19, 0x2c, 0xa3, 0x81, 0x19,
+	0xa8, 0xb2, 0x9d, 0x75, 0xb2, 0x30, 0xcc, 0x7c, 0xf4, 0x30, 0x76, 0xd9, 0x12, 0x11, 0xe8, 0xc9,
+	0x1a, 0xe0, 0x67, 0x9e, 0x28, 0xf0, 0x75, 0x75, 0x59, 0xb8, 0x62, 0x34, 0xf3, 0xed, 0x17, 0xc6,
+	0xd2, 0xe0, 0x1e, 0x9a, 0x15, 0x1a, 0xf6, 0x5a, 0x0a, 0x35, 0x96, 0xe9, 0x58, 0xfd, 0x40, 0xa0,
+	0x6b, 0xc8, 0x88, 0xc8, 0x25, 0x13, 0xa4, 0x5b, 0xc2, 0x5e, 0xf5, 0xf7, 0x0c, 0x49, 0xd7, 0x24,
+	0xc1, 0xf0, 0xa6, 0xc7, 0x42, 0x83, 0x11, 0xe6, 0x7d, 0x2a, 0xa2, 0x9e, 0x1c, 0x18, 0x8e, 0x62,
+	0xef, 0xee, 0xbb, 0x75, 0x97, 0x52, 0x10, 0xab, 0x74, 0xd0, 0x00, 0x5c, 0xd1, 0xf0, 0x59, 0xa9,
+	0x4f, 0x99, 0x4a, 0xf3, 0x8f, 0xa6, 0xb4, 0x98, 0x23, 0xc6, 0xb2, 0xf0, 0xb7, 0x99, 0x6b, 0x88,
+	0x7c, 0x08, 0x17, 0x9d, 0xd6, 0xe5, 0x50, 0xdc, 0x46, 0xc5, 0x9b, 0x59, 0x99, 0x19, 0x36, 0xcd,
+	0x52, 0x93, 0x24, 0x15, 0x55, 0xb8, 0x77, 0xe7, 0xd6, 0xc2, 0xde, 0xd6, 0x82, 0xb8, 0x6e, 0x89,
+	0xec, 0xd1, 0xb5, 0x38, 0x3a, 0x05, 0xfd, 0x68, 0x10, 0xf5, 0xdd, 0xe7, 0xbc, 0xfd, 0x06, 0x0a,
+	0xa4, 0x97, 0x4c, 0x26, 0xed, 0xf3, 0xf3, 0x4d, 0x6d, 0xd4, 0x3c, 0x4a, 0xd3, 0xae, 0x30, 0xdf,
+	0x15, 0xfe, 0xac, 0x3d, 0x1b, 0xe9, 0xae, 0xc5, 0xa9, 0x18, 0xdf, 0xfe, 0x92, 0xd3, 0x60, 0xd7,
+	0x1b, 0x5c, 0xd9, 0x1e, 0xad, 0x8e, 0xc0, 0x40, 0xc0, 0xb7, 0xe7, 0x42, 0x04, 0xb2, 0x49, 0x00
+};
+
+void oceanpar_decrypt(running_machine &machine)
+{
+	auto const src = reinterpret_cast<u16 *>(machine.root_device().memregion("user1")->base());
+
+	int const rom_size = 0x80000;
+
+	// not 100% verified
+	for (int i = 0; i < rom_size / 2; i++)
+	{
+		uint16_t x = src[i];
+
+		IGS27_CRYPT1_ALT
+		IGS27_CRYPT2_ALT
+		IGS27_CRYPT3_ALT2
+		IGS27_CRYPT4
+		IGS27_CRYPT5_ALT
+		IGS27_CRYPT6
+		IGS27_CRYPT7_ALT
+		IGS27_CRYPT8_ALT
+
+		x ^= oceanpar_tab[(i>> 1) & 0xff] << 8;
+
+		src[i] = x;
+	}
+}
+
+static const uint8_t amazonia_tab[0x100] = {
 	0x86, 0x00, 0xd2, 0x6b, 0x78, 0x79, 0xbc, 0x80, 0xc6, 0x8e, 0x9b, 0xd8, 0x3a, 0x52, 0x09, 0x15,
 	0x05, 0x57, 0x7a, 0x1f, 0x2f, 0x08, 0x47, 0xa0, 0x44, 0x4c, 0xf7, 0xbe, 0x3d, 0x59, 0xd1, 0x18,
 	0xac, 0xd5, 0xa0, 0x03, 0x2c, 0x34, 0xc6, 0x06, 0x08, 0x4e, 0x84, 0x94, 0x2b, 0x3f, 0x88, 0x08,
diff --git a/src/mame/igs/pgmcrypt.h b/src/mame/igs/pgmcrypt.h
index 4600b0583f3..421f72eb8b6 100644
--- a/src/mame/igs/pgmcrypt.h
+++ b/src/mame/igs/pgmcrypt.h
@@ -38,6 +38,7 @@ void superkds_decrypt(running_machine &machine);
 void pgm_decrypt_pgm3in1(running_machine &machine);
 void slqz3_decrypt(running_machine &machine);
 void fruitpar_decrypt(running_machine &machine);
+void oceanpar_decrypt(running_machine &machine);
 void amazonia_decrypt(running_machine &machine);
 void amazoni2_decrypt(running_machine &machine);
 void mgzz_decrypt(running_machine &machine);