(note: i didn't change the 1a6's to 1a7's because i am lazy. there's no code in level(init)1a6)

MAIN:
level1A7:
LDA #$FA
STA $1458
PHP
REP #%00110100
LDA $1C		; \
CMP.w #$0000	;  |  compare screen Y position

BCS VARH1A6	;  |  with $C0 - desired Y
BCC ZERO1A6

VARH1A6:
LDA $1C		; \
SBC.w #$0090	;  |  set layer 3 Y
STA $24		;  |  to $C0 - desired height
ADC #$001B
STA $24
PLP		;  |  if screen Y > or = the value:
RTS		; /

ZERO1A6:
 LDA.w #$0000	; \
STA $24		;  |  set layer 3 Y to zero
PLP			;  |  if screen Y < the value
BNE Return1A6
LDA $13D4
BNE Return1A6
LDA $13
AND #$03
BEQ Return1A6
REP #$20
DEC $22
SEP #$20
Return1A6:
	RTS

INIT:
levelinit1A7:
JSR level1A7
LDA #$04
TSB $40
LDA #$13
STA $212D
LDA.b #.Tidesa6
STA $00
LDA.b #.Tidesa6>>8
STA $01
LDA.b #.Tidesa6>>16
STA $02
PHK
PER $0006
PEA $84CE
JML $80871E
RTS

.Tidesa6
incbin tides.bin
	RTS