606 
PACIFIC SCIENCE, Yol. XV, October 1961 
TABLE 1 
Physical Characteristics of Divers and Nature 
of Equipment Used at Time of First Incident 
HOBSON 1 
MAU- 
TIN 
REESE 
Weight 
180 
195 
175 
Height 
5' 10" 
6'3- 
5 ' 9 - 
Skin color 
brown 
brown 
brown 
Bathing suit 
khaki 
none 
gray & white 
Swim fins 
light blue 
yellow 
black 
Mask 
dark blue 
white 
dark blue 
Snorkel 
green 
white 
black 
Spear 
Hawaiian sling 
none 
Hawaiian sling 
with 6 -ft. 
with 6 -ft. 
free shaft 
free shaft 
1 Same equipment in second incident. 
in order to face the onrushing shark. When the 
shark was very close he kicked it violently on 
the snout with his swim-fins. The shark veered 
away, circled once or twice behind Mautin and, 
upon the approach of Hobson and Reese, swam 
away. All three swimmers were now quiet in 
the water. 
Immediately after the first shark left the bot- 
tom, a second shark began to swim toward the 
surface on the same course as the first shark. 
However, after approaching approximately half- 
way, it returned to the reef floor. It is suggested 
that the cessation of commotion on the surface 
Fig. 1. Spatial relationship of divers to one another 
and to skiff above the coral reef at start of incident 
(white triangles) and at time of shark attack (black 
triangles ) . Letters beside triangles refer to diver which 
they represent, H — Hobson, M = Mautin, and R := 
Reese. Arrows indicate direction of movement of 
sharks. 
and the presence of three swimmers resulted in 
the first shark swimming away and the second 
shark returning to the bottom. 
Both Hobson and Reese were approximately 
20-30 ft. from Mautin at the time the first 
shark attacked; however, there was no indica- 
tion that the shark directed any attention toward 
them. It appeared that the shark was orienting 
to the agitation at the water’s surface caused by 
Mautin’s strong swimming. This observation 
supports the suggestion by Tester (I960: 183) 
and others that sharks are attracted by unusual 
commotion. A second possibility is that the 
shark was attracted to the bright yellow swim- 
fins which Mautin was wearing, but Hobson, on 
the basis of unpublished data, feels that this is 
unlikely. 
Mautin gained the impression that the shark 
came for him believing he was the wounded 
fish, and that competition from the other sharks 
resulted in the direct and swift attack not pre- 
faced by the usual cautious investigation. 
The four to five sharks were still swimming 
in the same excited manner in the vicinity of 
rock 2 when the divers left the water. 
SECOND INCIDENT 
A second incident occurred the following day, 
September 2. Again the time was approximately 
noon, the sky was clear, and the surface of the 
lagoon was calm with underwater visibility in 
excess of 100 ft. Fish were being speared in 
shallow water along the beach at Sand Island 
adjacent to the deep water channel leading into 
the lagoon from the east. Hobson was in the 
water, and John C. Kay, a graduate student at 
the University of Hawaii, was standing off the 
beach in a 16-ft. skiff with the outboard motor 
idling. Hobson speared a 10-lb. parrot fish (Scar- 
idae) which carried the spear shaft toward 
deeper water. About 35 yd. from the beach, at 
the edge of the reef, the bottom drops abruptly 
from approximately 15 ft. to over 100 ft. Grey 
sharks are common along this drop off. Hobson 
pursued the fish along the bottom, thus avoiding 
the surface commotion which had apparently 
attracted the attention of the sharks the day be- 
fore. He overtook the injured fish on the bot- 
tom at a depth of approximately 15 ft. on the 
edge of the drop off. When the trailing spear 
