  Oleg Viro introduced an invariant of rigid isotopy for real algebraic knots
in $RP^3$ which can be viewed as a first order Vassiliev invariant. In this
paper we look at real algebraic knots of degree $d$ with the maximal possible
value of this invariant. We show that for a given $d$ all such knots are
topologically isotopic and explicitly identify their knot type.
