Last year at the end of April-beginning of May I did 3 back-to-back liveaboards with BlueOtwo
www.blueotwo.com - the Northern Wrecks and Brother Islands route, the Deep South route and the Daedalus Reef & St Johns route.
The two latter trips (Daedalus Reef and St Johns in particular) were awesome. At Daedalus Reef we did 6 dives...and every single dive we had several hammerheads (one dive a school of 17 hammerheads) and just under our boats were 2-3 very curious oceanic whitetip.
On the South trip we had grey reef sharks, whitetip reef sharks, dolphins underwater (2 times), mantas (both daytime and night dives and 3-4 mantas looping around our mooring lines all night i the light from our boat lights).
Tip: If you go for a night dive down south and encounter mantas leave your dive light on...it will attract the small critters in the water...which in turn will attract the mantas...and voila you have 2-3 mantas doing looping right in front of you to scoop up as much as possible of the critters.
I really liked the diving with BlueOtwo...the dive guides are a mix of Europeans and Egyptians which makes for a very professional and western work attitude and joy in diving in the dive guides (I have had bad experiences with previous liveaboards with all-Egyptian dive guide staff)....and they give you very comprehensible dive briefings and then let you decide whether you want to dive just with your buddy or with a dive guide (I much prefer that to being forced to dive with some dive guide because sometimes with other boat companies you come across some dive guides who are a bit too much in love with the banger stick and just do the job for the money and have no special love for diving as such...but this was not the case with the BlueOtwo dive guides I must mention).
Also BlueOtwo have their Project Shark several times every month - there the German university doctor Elke Bojanowski is one of the guides and she makes short lectures each night on shark biology, shark behaviour, difference between shark species, etc. Well worth the money.
I am again this year doing 3 back-to-back liveaboards with BlueOtwo...end of April-beginning of May.
This year I will again do Daedalus Reef and the Deep South...these trips were spectacular this time of year last year, so I hope it will be the same this year.