It should be fairly easy.  Use inches rather than hexes and make yourself some turn gauges and fire arc templates and you should be there.

When we do non-hex naval wargames we use pre-plotted movement, so we write orders for all ships then move everything simultaneously.

I agree that you should be able to turn up to 60 degrees for each P or S you have put in your movement orders, but the thrust requirement for turns should be based on the number of turns you make not how far you turn (so two turns to port would have the same thrust requirement if they were two turns of 10 degrees each or two turns of 60 degrees each).  If you try to do it any other way I can see people claiming that they have only turned X degrees over the course of the turn and therefore only need Y thrust to do it.

Are you planning on using miniatures for your hexless games or counters of some sort?

I know exactly what you mean.

I find it odd that my gaming group is happy to use hexes for sci-fi games but would never consider it for historical games as it is "too confining".

Here are my proposal of the rules for playing without hexes. I hope I cover everything:
Starmada had been designed to play with hexes, which serve to regulate movement and ranges.

But, the rules may be slightly modified to play Starmada without hexes, especially if you play with miniatures starships.

In order to play without hexes, you have to take into account the following modifications:

-          Range (RNG). The usual range values are expressed in hexes. In order to play without hexes, you have to multiply those ranges by the size of a hex, a size you have to decide before play. For example, if you decide that each hex has a size of 5cm, a range of 9 will become a long range of 45cm, with a short range of 15cm, and a medium range of 30cm. Ranges between starships are measured by using the stems of the minis as a reference point.

-          Set-up: Starships are usually set-up next to a table border. Use the same conversion hex->cm to determine where starships can be set-up.

-          Movement orders: Those are not modified and are recorded normally. However, their implementation will be slightly different.

-          Moving on the board game:  Starship may move through hexes occupied by other ships without incident – space is big enough for them to pass. Further, if a ship ends its movement on the same position as another ship, the former ship must reduce its movement the least distance possible in order to be placed next to the latter ship and thus avoiding any overlapping of mini. If still unable to avoid the overlapping, it will have instead to move the minimum possible distance in order to go beyond that latter ship.

-          Movement resolution: A starship movement may include the possible maneuvers: Either a number, a P of S maneuver, a right or left shift, a pivot or a U maneuver. Each one will be resolved this way on a hex-less surface:

o   Number: As for the range value, the number is instead converted in a value in cm. Still using the 1hex->5cm conversion, a movement of 3 would mean that the starship will have to move 15 cm; except that the last ‘hex' of movement of a ‘number' may  be used to move any distance, between 1 to 5cm. Of course, if using less than 5cm for that last ‘hex' of movement would result in an overlapping of mini, the starship must move the minimum distance in order to avoid the overlap. Example: A starship move order is 3S2. It moves 14 cm (5 cm for the first and second ‘hex', 4cm for the last one for that number), turns left, then decides to move only 7cm (5 for the first hex of movement, 2 for the last one). But, by moving 2cm, the ship ends its move on another ship. It will either move less (1cm minimum) to avoid the overlapping, but if unable, will have to move up to 5cm for the last ‘hex' of movement.

o   P or S: Normally, such a maneuver means the ship is pivoted 60°, left or right respectively. On a hex-less surface, a starship may be pivoted UP to 60° per such maneuver. Following the previous example: After having moved 14 cm, the starship pivots 45° to the right, before continuing its move.

o   Shift: For sake of simplification, shifts are not used on a hex-less surface.

o   Pivot: For sake of simplification, each pivot will be exactly 60°.

o   U: As for a hex board, a U maneuver on a hex-less surface means that the starship is pivoted exactly 180°.

-          Order of movement: Starships are not moved simultaneously. After movement orders are recorded, but before moving them, determine the total number of starships on each side. The side with more ship has the first opportunity to move a single ship. Moves then alternate between sides until all ships has moved. If a side has at least twice as many starship, it will move two ships instead of one; etc. (this is essentially the same routine for combat). If both sides have the same number of starships, roll a die to determine which side goes first.

-          Firing arcs: Although they are not modified, it can be difficult to determine where a target lies according to the firing ship arcs. However, if the base of the mini is an hexagon, it shouldn't be problematic. The use of a template can also facilitate the determination of the position of the target relative to the firing arcs.

-          Fighters: When deployed, fighters are placed next to their carrier ship, as close as possible. When moving, unless bypassing obstacle, you will just have to measure their move and place them accordingly. In order to fire at a target, measure the shooting range between the stem of the fighter stand and the stem of the target ship as usual.

- Cloaking device. Here is a big problem, for which I don't really have a perfect solution.  One solution could be to let the staship on the board, but enemy ships are unable to shoot it. I don't reallike the solution, but it enables the player to move the cloaked ship as above. The other solution would be to remove the ship from the board, and when it reappears, it is moved from its last known position exactly as written, each P or S translated as a 60° turn, each straight movement exactly its value.

Marc

That is excellent news.  I don't have any ship models but I will try it out using the Iron Stars fold-ups as they have a central aiming point marked on them.

Have you tried ships with cloaking devices yet?  I was wondering about having dummy ships - when a ship cloaks it creates a number of dummy ships each of which gets it's own movement orders but only one if the real ship.  None of them can be fired on.  It avoids the hassle of removing the ship from the table and then trying to back-track movement when it decloaks, and stops the other side from following a cloaked ship around waiting to pounce when it decloaks.  However, it does mean more ships on the table.

I seem to remember that you could get clear plastic Star Fleet ships which would have been good for cloaked ships, but I don't know if they still do them.