See also
The semi-bluff raise is when you raise on the draw not necessarily to build the pot for value, but with the intent of taking down the pot without further action. This implies that you need to have some reasonable expectation that the bettor will actually fold, which means that the best candidates for a semi-bluff raise are the usual suspects: weak stabs, c-bets, or any other possible steal bets.
In low-SPR situations in which there are only two bets to play, the semi-bluff raise takes precedence over the float. In other words, if you choose to contest the pot at all, the default play is to shove.
But in mid- to high-SPR situations, the semi-bluff raise is more of an alternative to the float. And, much like the float, the weaker your draw, the more the play is dependent on your read of your opponent. In other words, you don’t need as strong a read on your opponent to raise with a 13-card nut wrap with a flush draw as you do to raise with a bare open-ended straight draw with a two-flush on the board.