I had no clue there was so much and varied dolphin symbolism
Protection
Good fortune
Love and Aphrodite
2 dolphins = friendship
Historical Christian; including Christ and the resurrection
http://traditionalcatholicism83.blogspot.com/2011/10/dolphin-in-christian-symbolism-among.html St. Brendan's Cross with 2 dolphins
https://www.seiyaku.com/customs/crosses/brendan.html St. Clement's or Mariner's Cross
https://en.wikipedia.org/wiki/Pope_Clement_I "We have this hope as an anchor for the soul, firm and secure..." - Hebrews 6:19
Cross, anchor and dolphin

Dolphin and anchor together symbolize the proverb
Festina lente which means "Hasten slowly" WHICH IS GOOD ADVICE FOR THE SHOOTER.