Answer: FEETFIRST

AnswerCrossword Clue
FEETFIRSTOne way to jump in
FEETFIRSTOne way to jump
FEETFIRSTEntry mode for full gainers
FEETFIRSTOne way to jump in a pool
FEETFIRSTOne way to land
FEETFIRSTOne way to land (and puzzle theme)
feetfirstwith feet leading the way