[Coral-List] Underwater Drill

Georg Heiss georg.heiss at reefcheck.de
Tue Feb 20 10:32:21 EST 2007

Dear all,

we used hand-held pneumatic drills with great 
success. See below excerpt from a publication of 
With some care we could use them for years: run 
the drill after use with air to remove salt 
water, soak in fresh water, clean again with air, 
then put oil everywhere inside the drill and run 
it briefly to distribute the oil inside the 

All material is standard toolshop stuff, except 
the drill barrel, which is also standard, used 
mostly for drilling holes in walls for 
electricity outlets.

For photos, see 
(lower part of the page). I can also send a photo 
of the drill and drill bit in higher resolution.

Best regards,

Heiss, G.A., Dullo, W.-Chr. and Reijmer, J.J.G. 
(1993): Short- and long-term growth history of 
massive Porites sp. from Aqaba (Red Sea).- 
Senckenbergiana maritima, 23/4/6: 135-141.


Materials and Methods

Several attempts of underwater coring are 
recorded in the history of coral reef research. 
The dimension of the operations as well as the 
means used vary. 
After the early rude method of blasting reef 
sections, hydraulic submersible drills have 
widely been used with great success (MACINTYRE 
1975; HUDSON ET AL. 1976; HUDSON 1977; DRUFFEL & 
1984; BARNES & LOUGH 1989; WINTER ET AL. 1991; 
The first drill for underwater coring driven by 
pressured air is described 1975 at Lizard Island, 
Great Barrier Reef (DAVIES & STEWART 1976) but as 
far as we know, no study on cores obtained with 
this drill has been published. In contrast to 
their drill we didn't use an impact tool and we 
could work independently from a boat. Further 
attempts were made by (STEARN & COLASSIN 1983) 
who gave a description of an underwater pneumatic 
hand drill. (POTTS ET AL. 1985) took short cores 
(10-15 cm long) of Porites with a hole saw welded 
to a 30 cm pipe and mounted in a pneumatic drill. 
At Curaçao the growth rates of Montastrea 
annularis were recently studied on cores taken by 
a pneumatic drill similar to our equipment 
(BOSSCHER 1992).

The intention was to build a simple, cheap and 
small coring tool, which can be operated by one 
Scuba-diver independent from any supply on the 
sea-surface. We wanted to avoid some 
disadvantages of the already described machines 
for our field work as there are the large size of 
some and therefore the limited mobility and/or 
the need of energy support from a boat. A 
technique for gaining long coral cores with a 
handy instrument has been developed.

Besides sampling of several smaller individual 
colonies over the depth range to 45 m (HEISS in 
prep.) we wanted to get records on growth rate 
and proxy dates over a longer period. Another 
important objective was the possibility of 
comparing with other long-term growth records in 
corals in other localities of the world. In the 
last 20 years several successful attempts of 
large scale coring in living corals have been 
& LINICK 1978; MACINTYRE 1978; HUDSON 1981; 
DRUFFEL 1982; ISDALE 1984).

Field work
Due to the availability of Scuba-tanks and the 
need for easy handling from small boats we chose 
compressed air as the best power source for the 
drill. A commercially available RODCRAFT 
4200-pneumatic drill was selected on the basis of 
its size and technical characteristics. It works 
at a speed of 2000 rpm with an air consumption of 
220 l/min under full power. Although the 
operating pressure is 0.6 MPa (6 bar, 
manufacturer's information), we operated the 
drill at a pressure of 8-9 bar which is the 
pressure supplied by an ordinary first stage 
regulator for Scuba-diving. We used in the first 
year a SCUBAPRO Mark II first stage. We later 
improved the system by using a balanced first 
stage (SCUBAPRO Mark X) in order to have a better 
air supply in water depths greater than 10m. The 
air came from 15 l dive tanks, pressurized to 200 
bar, which provides an air capacity of 3000 l. 
The connection between tank and drill was a 
standard industrial pressure hose of 2 m length. 
The core-cutter is a diamond-tipped steel tube of 
300 mm length and an outside diameter of 41 mm 
(36 mm inside) manufactured by DIA-G 
Diamantwerkzeuge GmbH, Kiel.
With this composition of the instrument we could 
easily obtain cores of 30 cm length from 
different massive growing genera like Platygyra, 
Porites, Hydnophora, Favia and Favites. 
The initial millimeters were drilled by turning 
the core barrel by hand several times on the 
coral surface. No template was necessary for the 
drilling procedure. Drilling of one 30 cm core 
took only a few minutes. Depending on the 
rigidity of the coral we could obtain up to four 
cores out of one 15l-tank.

At 13:25 Uhr +0000 14.02.2007, aj.martignette at comcast.net wrote:
>I have to drill some holes in pilings for large 
>bolts that will be used to mount water quality 
>sensors. I would like to avoid having to drill 
>them with a hand drill. I know that you can use 
>a pneumatic drill hooked up to a scuba tank. I 
>was wondering if anyone had details on a setup 
>they use and any modifications that are needed 
>to the drill.
>A.J. Martignette
>Research Assistant
>Marine Laboratory
>Sanibel-Captiva Conservation Foundation
>900A Tarpon Bay Rd.
>Sanibel, Fl 33957

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