My favorite is the 1st one because of the use of the word “mate.” You could segue this into a theme of the sailor’s mate being the anchor away from the ship:

1. “Success in marriage does not come merely through finding the right mate, but through being the right mate. ” ~Barnett R. Brickner

I also like this next one because you can tie in the “threads” notion to the building of a rope with knots that sailors use to secure a ship just as you would bind threads of a relationship to secure your marriage:

2. “Chains do not hold a marriage together. It is threads, hundreds of tiny threads which sew people together through the years.” ~Simone Signoret

I couldn’t think of how the rest of these could tie into your presentation, but I included them in case you might find any of them useful…

3. “The sum which two married people owe to one another defies calculation. It is an infinite debt, which can only be discharged through eternity.” ~Johann Wolfgang von Goethe

4. “[W]hen you realize you want to spend the rest of your life with somebody, you want the rest of your life to start as soon as possible.” ~Nora Ephron, When Harry Met Sally

5. “If you were going to die soon and had only one phone call you could make, who would you call and what would you say? And why are you waiting?” ~Stephen Levine

6. “A man without a wife is like a vase without flowers.” ~African Proverb

7. “More marriages might survive if the partners realized that sometimes the better comes after the worse.” ~Doug Larson

8. “Love seems the swiftest but it is the slowest of all growths. No man or woman really knows what perfect love is until they have been married a quarter of a century.” ~Mark Twain

9. “Once the realization is accepted that even between the closest human beings infinite distances continue, a wonderful living side by side can grow, if they succeed in loving the distance between them which makes it possible for each to see the other whole against the sky.” ~Rainer Maria Rilke

10. “A successful marriage requires falling in love many times, always with the same person.” ~Mignon McLaughlin, The Second Neurotic’s Notebook, 1966

11. “Don’t marry the person you think you can live with; marry only the individual you think you can’t live without.” ~Dr. James C. Dobson

For future reference, the best site I’ve found for searching quotes is http://www.bartleby.com/quotations/

just a suggestion…