Ahh... no Kathulu fan can go without Hornblower. But Honorverse you say is similar? Hmm... I'll reaserch into that one...
Honorverse is basically Hornblower...inSPACE! David Weber drew more than a lot of inspiration from it. The Star Kingdom of Manticore is basically the sixteenth century United Kingdom with twenty-fourth century firepower. He did diverge from the formula when he realised how much his fanbase loved most of the characters who were actually supposed to be killed off but were left alive. Honor Harrington herself being one of those characters who were marked for death. Not that she hasn't been maimed severely in most of the books...
The best thing about Weber is he and his publisher actually put most of his/their books up for free. Baen are like the stardock of the literary world. A few of the Honorverse series are available. Start at the beginning with On Basilisk Station. They only get better from that point on. I'm basically peeing myself waiting for the next instalment.