Many kinds of instability
If you could tell for sure that the boat had one end not floating in both of the OPer’s tries, I commend you on your perspicacity. Pushing off with a foot combined with the seat thing sounded more like the OP being high and off center in general, a problem whether or not floating.
daggermat, the longer I’ve paddled,
the worse a model I’ve been for newbies on how to enter a boat. And the same is true for many experienced whitewater paddlers. With experience, the wrong ways work fine, and “the right way” no longer feels right.
I guess we just gotta set a bad example.
ockham sometimes only shaves one side…
“Seriously? Anyone here heard of Ockham’s razor?”
Well, that’s a useful tool, but it’s not a be-all-end-all principle. The fact is that Ockham sometimes only shaves one side of his face. If the question comes from his right, that’s all he bothers to shave.
Or, to put it like Wikipedia, “A superficially simple phenomenon may have a complex mechanism behind it. A simple explanation would be simplistic if it failed to capture all the essential and relevant parts.”
Keep in mind that the usefulness of a public forum is that readers other than the OP may have the same or a similar question. Thus, it makes the board more useful when respondents answer questions fully, rather than simply try to get the OP on track.
In the present case, several posters including myself noticed that one end of the canoe was on the ground in the description. However, that was such a simple solution that we did not stop with correting that flaw, but went on to describe procedures that could also handle other sources of instability - which, it appears, the canoe in question did in fact have.
Thus, I don’t think this completeness in the answers is something to criticize the community for - rather, it should be praised as it makes the forum more useful for more people.
Furthermore, as it turns out, the OP didn’t have the end on shore both times, and so if everyone had limited their answers to that point, we wouldn’t have covered his actual experience.
Now, I don’t intend this response to be a flame of your post. In fact, I think your approach is better in certain circumstances, namely one-on-one type instruction or conversation, especially at waterside with the subject in question right before you. However, if you factor in the time delays and the wider audience of a message board, I hope you will see that a more comprehensove answer is helpful in these forums.
Maybe a little over reacting?
Did anyone mention perfectly parallel? No. The suggestion was to float the boat with the side toward the shore, rather than with the bow or stern still on the shore.
Of course, the steepness of the bank or shore is also a factor in whether a partially beached entry or exit is practical or not. It’s not practical in most of the places that I paddle.
For me, the pointy end of a canoe on shore = wobbly.
Floating in water = less wobbly.
Some boat shapes are better suited to otter launches and partially beached launches.
Thanks for the good laugh.
c’mon man
I allowed half a degree!! 
And 1" total tolerance on depth! Must be getting mellow in my old(er) age, though sometimees the inner spaz still shines through.