In sonnet 130 there is one line with 11 sylabbles ,this line is number 13.
"and yet, by heaven, I think my love as rare"
He uses 11 sylables because he metions the word rare and having 11 sylable is is rare in a sonnet. it is like the "odd one out" line in the sonnet, and because of this it must mean something, it says things without saying it.
In sonnet 116 there is also a line will 11 sylabols, this is line 6.
"that looks on tempests and is never shaken"
This line could suggest that Shakespere is saying that love can overcome everything as long as it is togather. This sonnet has 3 lines with 11 sylabols , this is still rare like sonnet 130 bu t not as rare. A tempest is a storm at sea, so if a ship is at sea during a tempest it will get shaken but love can out balance this.