START:0,1,0
1:-10,0,0
2:-10,0,-5
3:-20,-1,-5
4:-30,-1,-5
5:-40,0,-6
6:-50,0,-6
7:-60,0,-6
8:-70,0,-6
9:-80,0,-6
10:-85,0,-6
11:-85,0,-15
12:-95,0,-15
13:-105,1,-15
14:-115,2,-15
15:-120,3,-15
16:-130,1,-15
17:-140,2,-15
18:-145,3,-15
19:-151,2,-15
20:-155,1,-15
21:-165,1,-15
22:-175,0,-15
23:-180,4,-15
24:-185,9,-15
25:-190,8,-15
26:-195,-1,-15
27:-195,1,-25
28:-200,1,-30
29:-210,-1,-30
30:-220,1,-30
31:-230,0,-30
32:-230,0,-40
33:-240,-1,-40
34:-240,1,-50
35:-240,1,-55
36:-250,1,-55
37:-260,2,-55
38:-270,1,-55
39:-275,3,-55
40:-280,1,-55
41:-285,2,-55
42:-290,0,-55
43:-300,0,-55
44:-310,0,-55
45:-320,0,-55
46:-330,0,-55
47:-340,-1,-55
48:-340,-1,-65
49:-340,0,-70
50:-350,6,-70
51:-360,0,-70
52:-365,0,-70
53:-370,0,-65
54:-380,0,-65
55:-385,0,-70
56:-390,5,-70
57:-400,8,-70
58:-405,5,-75
59:-410,4,-80
60:-415,1,-85
61:-420,1,-85
62:-430,-1,-85
63:-440,0,-85
STOP:-444,0,-85

I think it's 1:8 scale. 444/16=27.75, 85/16=5.3125, but that put me on a tree halfway.
444/8=55.5 (56), 85/8=10.625 (10), and this put me down in an unexplored cave, which came up in the lake just outside the base. About 16 blocks short? Odd. Might move the portal back one or two spaces and see what it does.