It is very common, particularly amongst Australians, to confuse Tack and Tact in the context of comparing two different courses:
Thus
Erroneous: He took a different tact to me instead of
Correct: He took a different tack to me.
Comparison chart
 | Tack | Tact |
|---|---|---|
| Usage | Tack refers to direction | Tact refers to avoiding giving offence |
Definition of Tact
tact : noun
1. a keen sense of what to say or do to avoid giving offense; skill in dealing with difficult or delicate situations.
2. a keen sense of what is appropriate, tasteful, or aesthetically pleasing; taste; discrimination.
Definition of Tack (in this context)
tack1 : noun
1. a course of action or conduct, especially one differing from some preceding or other course.
2. one of the movements of a zigzag course on land.
Few 
Affect 
Compose 
Jail 
Envy
Comments: Tack vs Tact