Spot Heights or Not?

Master Navigators only

TC1A @ 825 531

From TC1A proceed via the following instructions using disguised spot heights.

- - 5? 5? 12 5? - - - 6 - 13 - - - 17 8 - 11 4 8 - 7 - 7 - 7 - 7 8 - 5

TC2 @ ETL in 7349.

Route Checks
RC6 GN, RC7 T, RC8 ^, RC9 YOO, RC10 RD

(See regulations for Route Check meanings)

RC6 = List the blue Grid Numbers crossed on the route.
RC7 = How many Telephones within 200 metres of the route?
RC8 = How many gradient arrows on the route?
RC9 = How many Yellow/Orange/Orange junctions on the route?
RC10 = How many Red Diamonds crossed on the route?

Solution 2

Each plot referred to the sum of the digits of the spot heights in a kilometre square to be used. Half of the dot for SH109 is considered to be in 8152 and half in 8151.

Via the following Grid Squares, features and Route Checks.

8253(- no SHs), YOO(1), 8252(-), YOO(2), 8152(1+0+9=10/2=5), 8151(1+0+9=10/2=5), YOO(3), 8051((+3=12), 8151(1+0+9=10/2=5), T(1), YOO(4), 8150(-), 8050(-), 8150(-), GN1, T(2), 8149(1+2+3=6), 8049(-), RD(1), 7949(8+5=13), RD(2), > (No!), 7950(-), 8050(-), YOO(5), GN0, 7950(-), GN8, YOO(6), GN9, 7850(9+8=17), GN7, YYOO, YOO(7), 7750(1+1+6=8), YYYOO, T(3), 7751(-), 7651(7+4=11), 7650(1+1+2=4), YYOO, (GN7 doesn't break the line of the road?), 7750(1+1+6=8), GN7, RD(3), 7749(-), 7649(5+2=7), 7648(-), 7649(5+2=7), 7549(-), 7548(3+4=7), 7549(-), 7548(3+4=7), 7448(1+7=8),  7449(-), 7349(2+3=5)