5. Drop Site andCurrent Determination
With GPS the drop sites will be almost always very precise,however, consideration of the divers descent ability may dictate having thecapitan drop further south, say when one diver has trouble clearing. The divemaster should always enter the waterfirst to check the current direction and if possible check the accuracy of thecapitan’s drop site.
6. Interests
It is the job of the divemaster to sense the generalinterest of the clients so that he can focus the dive on scenery ornature. Even if there is no consensus,let the clients participate in the choice of focus. In almost all cases everyone will nod in approvalof the choice the divemaster helps them make.
7. Environmental Considerations
The dive briefing must include information about both thelegal and ethical issues in maintaining the health of the reefs. Thorough discussion of National Park rulesare a must and should be augmented by our own, possibly more restrictive. It should be made very clear that we place ahigh priority on protecting the reef and that any violation of the rules willnot be accepted.
8. Naturalist Dives
The Aldora Divemaster must include animal identification andinteraction whenever possible. Erasable Slates are provided so that thosecommunication skills are enhanced.
9. Signature Dive Site Scenarios
The following are suggested scenarios for our best divesites. They are intended to illustrate ahigher quality dive made possible only by our use of big tanks andcomputers. The Aldora Divemaster must,however, use his own judgment in carrying out any dive plan.
a. Punta Sur Devil’s Throat
The dive briefing should explain the importance of thedescent, the need to minimize sand kicked up, and the great importance of thesafety stop. Descend as a group to the entrance of the Devil’s Throat cave thencheck air supply and readiness of all divers. Then proceed slowly into theroom, pause so that all divers can see the hole, then lead the group down.
Depending on how long the descent took, exit either theshallow(120ft) or deep (129ft) holes, and rise to the entrance of theCathedral. When the last of the groupexits the Devil’s Throat enter the Cathedral, waiting on the knees in the sanduntil most others enter. The divemastershould then illuminate the Cross for a few minutes before proceeding out to theentrance of the Plunge. If thedivemaster’s no-deco time is more than 10 minutes the Plunge can be taken butall must quickly rise since the 5 minute barrier is usually encountered at thebottom of the plunge.
Once out of the Plunge the ascent should start, just passingChristmas Tree Coral then winding up around the tops of the coral heads. Checkair supplies at this time. Leaving the last coral head of Punta Sur the groupshould be at about 60 feet which will allow them to cruise the tops of ColumbiaDeep, once the crossing is made. It isabout this time that the heavy breathers may be close to 1000 psi and it isappropriate for the divemaster, or others to share air...in a controlledsituation before any emergency or buoyancy problem could occur. The one offering the air should deplete hisair to a level no lower than the heavy breather. At about 40 minutes into the dive the finalascent to the safety stop should be made. At this point the divemaster should be especially attentive for any signof uncontrolled positive buoyancy. Agood practice is to start the safety stop at 15-20 feet for 5 minutes then riseto 15. That way, even if someone losesit at 15 feet they will at least have had a pretty good stop. After the safety stop exit in the normal way.
b. Punta Sur Sur
The briefing should contain all the elements of any deepdive, like the Devil’s Throat, then explain the sights to be seen. At Punta Sur Sur the current is frequentlyoscillating and it is really important to drop in the right place. If the current is strong to the north then adrop over the sand, somewhat to the south of the first ball works well. But if the current cannot be determined thenit is always safer to drop right on the first ball. Most swimthroughs at Punta Sur Sur can beenjoyed in the 100-120 ft range. If thecurrent is strong and the pace quick it is frequently possible (based onno-deco time left greater than 10 minutes) to go through the Devil’s Throat Cave and cross over to the Cathedraland then up in the normal Devil’s Throat manner. In no case should either the Devil’s Throator the Plunge be attempted on a Punta Sur Sur dive. The ascent is much the same as the Devil’sThroat but much more latitude exists for checking air supplies and status ofthe divers.
c. Columbia Deep
Columbia Deep has many of the same aspects of PuntaSur. The first wall of Coral extendsabout 1 kilometer from north to south. It is best to hit the sand on the south end on descent but if it ismissed just descend over the wall to about 80 feet. The sand side is not very interesting andthere are no swimthroughs, so going over the wall is the only choice. Staying at about 80 feet one encounters theend of the first wall, the northern end of which is one of the more beautifulsights in Cozumel, what we call Cathedral Norte. At that point the best view is from 105 feet,knees down in the sand looking up at sunlight filtering through big cracks inthe coral head, with fans of Black Coral waving in the current. This is a good opportunity to check airsupplies and diver condition. Onceeveryone is o k, then enter the base of the coral head and go through theswimthrough. With good divers you mayturn to the right and circle back into the entrance, but with novices or onesthat would kick up sand just go straight thru.
When finished with the major swimthroughs go out to the wallagain and under the big arch. At the bottomof the arch is Dave’s Throat which empties out at 130 feet. There is a beautiful green coral there thatis unique. Novice divers may wait at thetop of Dave’s Throat. The best way fordivers to descend Dave’s Throat is to dump air and go down head first. The dive master should wait at the bottom ofDave’s Throat to make sure that all divers fill their BCs and ascend onexiting.
Once leaving Dave’s Throat the group should all rise to thecoral head tops at 50 feet. Two smallgaps will be encountered but on this dive it is possible to stay in nearconstant contact with the coral heads, all the way up to 30 Ft. at the start ofnormal Columbia. Over all dive time should be more than 1 hour.