Getting dunked in the solo tank is a tradition most, if not all, Air Force pilots experience after their first solo in a military aircraft. It seems Mission Aviation Fellowship has a similar tradition.
You can see the pictorial story of Aaron Hoffman, a recent arrival to Kalimantan, who landed his float plane after his first in-country solo as a mission pilot.
He probably should have worn his life vest.
Kalimantan is in Indonesia, and shares an island with Brunei.
See more at the MAF Blog.