so what's the answer? dived? dove?

Strictly speaking, the answer is neither.

SCUBA stands for "Self-Contained Underwater Breathing Apparatus".

You can use it in shallow water, or simply by floating face-down as with a snorkle.

When using a snorkle, one does not snorkle-dive. You go snorkling.

Lowe should have said "We SCUBAed with sharks".

In the present tense, one says "Let's SCUBA", just as one would say "Let's Bomba".