How Big Do Tiger Sharks Get?
Having spent countless hours in the water with Tiger Sharks at Tiger Beach over the past decade has been an incredible experience. These sharks are fascinating in so many ways. We have the opportunity to learn so much about the individual animals, from distinct markings to personality characteristics. But one question people always want to know…how big is the biggest tiger shark?
The tiger shark commonly reaches a length of 325-425 cm (10-14 ft) and weighs over 385-635 kg (850-1400 lbs). Length at birth varies from 51-76 cm (1-1.5 ft). Males reach sexual maturity at 226-290 cm (7-9 ft), while females become mature at 250-325 cm (8-10 ft) (Compagno et al. 2005). The largest specimens attain lengths of over 5.5 m (18 ft) and are estimated to weigh over 900 kg (2000 lbs).
— Florida Museum
So, have we ever seen an 18 footer swimming around at Tiger Beach? Nope, but pretty close! The most famous shark, Emma, is estimated to be between 14 – 16 feet long! She was named over 20 years ago and was a fully mature shark at that time. She has been a favorite of divers ever since and we have seen her both while pregnant and between gestations.
Tiger Shark Research Article
In an original research article published in September of 2021, teams deployed acoustic tags in 48 tiger sharks. Scientists placed forty-one of those tags off the coast of Grand Bahama Island, where Tiger Beach is located. Of the remaining sharks, researches tagged 5 off South Carolina and 2 off Florida. They also collected a number of scientific data points, including:
- pre-caudal length
- fork length
- total length
- life-stage (maturity & pregnancy)
With accurate scientific measurements of a large sample of the sharks we dive with, in the location we dive with them, we can really get a good sense of their average sizes. Let’s look at what the data shows.
Out of the 48 tagged sharks that, only 4 of them were male. All 4 of these males were tagged off Grand Bahama Island near Tiger Beach. Three of the four were mature sharks nearly identical in size (11.4, 11.5, 11.7 feet) while the 4th was immature and only measured 4.7 feet long.
Of the remaining 44 female sharks, scientists found 15 (34%) to be pregnant either by ultrasound or hormonal analysis. The largest female shark had a total length measurement of 12.7 feet (387 cm) and she was pregnant. There were several other female tiger sharks right around that same size that were not pregnant. The smallest female measured 4.9 feet long. Taking away the smallest male (4.7 ft) and female (4.9 ft) tiger sharks, the remaining 46 sharks were all 7 feet long or larger. Taking a look at all 48 tiger shark recorded lengths, the average was 10.6 feet long. Digging a bit deeper, the data shows that the 5 sharks tagged off South Carolina were larger than the average size measured. The two tagged off the coast of Florida were significantly shorter than the average (4.9 ft and 8.8 ft).
We’ll be diving a bit deeper into this research article in an upcoming post, but really found this one aspect of the study to be interesting and relevant to our dives.
To learn more about this and other great shark research, check out the University of Miami’s Shark Research Website.