jbd:
Its best to open them and clean them out on land.
Can't do that with my club, our rules state that they must be intact & unmarked at the start of the dive. Keeping them under control & not losing the parts you cut out (losing them is disqualifies you) is part of the challenge.
I've found that it works better to be seriously overweighted myself. It doesn't do any good at all to have an extra 10 lbs of lead in my goodie bag with the pumpkin, when I have to stay down while holding it after taking it out of the bag.
A small, sharp knife works better than a big one. It's real easy to cut yourself so take great car to avoid that. Figure out your design well b4 the dive so it's fixed in your mind how you're going to cut it.
This is a post I made about last year's contest:
We held our annual Pumpkin Dive at Morrison Spring, FL last month. This is a combination dive & cookout. Anyone who wants to can bring a pumpkin & enter. It's a 20 minute dive, only dive knives may be used. All pumpkin parts must be brought back & at least one piece if trash collected. All cutting must be done while diving, and no patterns may be drawn on the pumpkin.
Getting geared up:
At water's edge at the spring:
Post dive results (I never cut this image before, saw a picture of it & thought it looked doable while diving & a shark is a diving image. Should have chaged the shape of the tail, I don't like the sweeping away look):
All 9 entries:
Mine:
The Pumpkin That Looks Most Like George (George is our Zen guru technician, 78 years old):
The Pumpkin That Looks Most Like George, with George on the left, the carver on right:
I won a mask & snorkel for my shark pumpkin: