More on dump etc.

I thought dive, dump etc were securely within Schrijver's language of geminates (Pokorny says *dheu- with extensions the base attested in IIr and Greek). Then I find this:

Prellwitz
Etymologisches Wörterbuch der Griechischen Sprache

'bápto: dive in (Hom.),
baphé dyeing (Aesch.),
bapheús dyer,
búptein: baptízein (Hes.),
dúpto: (Ap. Rh.),
dúpte:s (Kallimach.) diver;
biptázo: (Sophron, Epich.) :

ai. gabhi:rá-s tief, gambha(n) n. depth, abyss;
an. kvefja dive in, sink down,
ags. cvabbe swamp,
ostpreuß. Quebbe,
mhd. erqueben suffocate.
root: gebho dive in.
Fick I4, 34 sees it also in géphura.
Vgl. Bechtel Hauptprobleme 114.
Scheftelowitz BB. 29, 15f. 38 adds
armen. cov sea, lake (*gebhu-),
covanam dive under.'

This stumps me.
Are those bap-, bup-, dup- (-t- is from -j-) related?
If so how?



Torsten