Answer
$3.05~m$ above the water with a speed of $5.144~m/s$.
Work Step by Step
See conversion factors (inside front cover).
$1~ft=0.305~m$. So:
$10~ft=10\times0.305~m=3.05~m$
$1~nautical~mile=1.852~km$, $1~km=1000~m$ $1~h=3600~s$ and $1~knot=1~nautical~mile/h$. So,
$10~knot=(10~nautical~mile/h)(\frac{1.852~km}{1~nautical~mile})(\frac{1000~m}{1~km})(\frac{1~h}{3600~s})=5.144~m/s$.
