We just finished our first week in Bonaire and are very experienced divers overall. So, while no "expert" like the many repeat Bonaire divers, I will still offer this.
I would be VERY careful about any East side shore dive, and would never, ever solo it (I solo occasionally and would personally consider it foolish to the point of self-destructive to attempt an East side solo). The "easiest" site, Cai, is huge, doing it without a guide you could spend two hours not really seeing anything. Most important, even Cai is subject to various currents, countercurrents, reverse currents, and mild to very strong surge. The "out" and "back" routes are very different, and can change with sea and current conditions, and are not necessarily tied to an easy swim through the channel. Currents can change unexpectedly during the dive (it did during ours).
My wive and I dove the Cai shore dive with Bas Tol last Friday. He was absolutely superb, knows the site like the back of his hand, knows where the good critters are (large and small).and Bas knows how to adapt to conditions and pick routes to get you out and back in with minimal effort and maximum safety.
Also, for those who like independence, Bas takes only one or two people and will do whatever dive you want. He even suggested that we recommend 100 cf tanks as he likes to maximize dive time (which we did). His price is $50.00 per person for the two of us, which we found very reasonable given his expertise, experience and ability to get us to the "good stuff." The dive was far more challenging than any west side dive we did all week, but we felt safe and in good hands.
As for tides, we asked Bas this very question when deciding which day to go. His response was that tide makes almost no difference. Far more important is low seas. As others have noted, Bas confirmed that higher waves send more water over the reef, and the north channel is the only significant outlet. More seas mean worse outgoing current, which complicates both the exit and the return. So, don't bother with the tide charts, just wait for a calm day.
If I did the site two or three times with Bas, and really talked to him, I might feel ready to do it on my own (never, ever solo) only in ideal conditions, but even then, consider this is real wild side diving. Very rough seas generally, and often no boat presence at all. This is not the benign west side, where you have no currents sweeping out to sea and nice calm conditions if you have to surface in an emergency or to take a bearing. If you have to surface on the west side, you are in real trouble.
Also, the White Hole and Funchi sites are only accessible by boat. The barrier reef at Lac bay is quite long and these sites are near the midpoint, not reachable diving from the Cai or Sorobon beaches. It was too rough the week we were there to get out on the boat. In fact, Bas kept us waiting until Friday for the wind to calm down.
In case it was not clear, I recommend Bas Tol completely.
