The Open Catch Bag
There are a variety of different catch bags, some close with velcro, some with zippers, and others with latches. Whatever is the case be sure that yours is securely fastened.
If you can convince a friend to do it, having a bag man can be very useful. This will increase your mobility and allow you to more easily catch those pesky lobsters. Plus not only do you get to blame him if the lobsters escape but if the ghost lobster happens to appear it will be the guy holding the bag full of lobsters he will be pissed off at, not you.