Advice on liveaboard in Cocos

My husband and I want to go to Cocos Island in 2027, we mainly want to see big schools of hammers. We spotted a nice discount on the Cocos Island Agressor for March 2027, and I have 2 questions:

• did anyone visit Cocos in March, and how was it? We read that there's more chances to see big schools during the summer months, but that the water may be turbid. It's a hard choice between clear waters but less sharks, and big schools with so-so viz. We also read about people seeing tons of hammers in dry season and others having great viz during summer.
• has anyone been on the Cocos Island Agressor? A friend told us it's not very robust and may not be suited for rough seas. However the reviews don't seem to mention that aspect. Thanks in advance for your tips :)