Q.Can we alter our course to port side for a crossing vessel on our starboard side ?

Answer 1 Answers

Hi! 

Your question doesn't provide sufficient information. Nonetheless, I'm assuming it's Rule 15 you are referring to. 
If, 
1. Both vessels are in sight of one another, 
2. Both vessels are power driven, and 
3. The risk of collision exists (obviously- ha ha), 
yes, you can! 
Make sure you do not cross ahead of the other vessel, and also, achieve an adequate CPA.