OK ....
As a genuine, honest to goodness, twenty five years at sea, sea dog I'll take the heat on this one and step up to the task.
[Us seadogs [well maybe not all BUT a high percentage of us ....] are sorta familiar with this particular subject .... we've paid darned good money to learn these lessons from the "pros" don't ya know ....

]
Ahem ....
Gaurd Duck .... the jokes are all sexual activity based. [premature ejaculation and subsequent flaccidity in both cases]
The joke was ... "a
minute man" .... meaning not able to last more than
a minute while in coitus. [having sex]
"Substantial penalty for early withdrawal." [Wink wink]
Has to do with the lady involved being extremely upset by that "early withdrawal".
Am I getting through ?
I am not trying to embarrass .... I am honestly trying to explain the jokes while still maintaining the PG 13 rating.