- Alternating bounds - Side A moves first each turn followed by Side B. This was used in the WRG Renaissance Galley Rules (the ancestor of the whole DBA family). It works for the galley periods, but not for sail and steam eras.
- Alternate ABBA (no not the group, they sang about Waterloo not Trafalgar) - side A moves first this turn followed by B. Next turn B goes first and then A. This was used as the default in General Quarters 2 (the first GQ ruleset for WWI). It's simple to apply, allows for alternating initiatives and works well in the steam era when ranges are much larger than movement distances.
- Initiative die rolls - each division rolls a die (which can be modified for command ability) and move in the order highest to lowest. David Manley uses this in several of his rules. It work especially well in the pre-dreadnought era as it allows the Japanese and US navies to get the jump on their Chinese, Spanish and Russian opponents.
- Leeward to Windward - used in the WH Trafalgar rules, this works well for age of sail as it gives the advantage to the fleet to the windward (as was historically the case). I think you need house rules for squadrons sailing upwind in line ahead (a common tactic historically) as the way Trafalgar is written you'll end up rear-ending your squadron mates.
- Reading through accounts of WWI actions, I've wondered about reversing this for coal fired ships - having the downwind ships move first. This gives the advantage to the side with clear vision (as funnel smoke blocked the LOS downwind).
- Drawing Cards - allocate one card per squadron and draw them one at a time each turn. This was used in various incarnations of MacDuff, and I've seen it elsewhere. I've never tried it at sea but it worked well on dry land and provided a real source of tension. A modified version appears in David Manley's "Form Line of Battle".
- Action based systems - 15-20 yrs ago (OMG I'm getting old) I wrote a set of WWI rules that used an action based movement system. Players selected a type of action (such as Open, Close, Flee etc) and moved in sequence. It worked quite well in practice and most players found it intuitive to use. I'll post the full system soon.
Any others out there?