Hi Fred

Used to race the H-18 { a couple decades ago} singlehanded at times and could right it in wind but weigh 225 and am fairly tall ,and that was before the heavier comp tip was added or changed ,retrofitted on all H masts .

The power righting pole is a good one as suggested -it simply swings out from under a fold up position under the tramp and provides added leverage to make righting easier

Weights or evan waterbags are very ackward and potentially dangerous I think ,with the potential to get caught up in them as the boat rights over towards the skipper.

SC =Aquarious Sails makes a great sidestay lever arm extender ,-you pull a fast pin out ,-that extends the stay and allows the angle of the capsized cat on its side to ease the righting weight amount needed ,--once up make that stay the leeward one {tention off} then use the little lever mechanism to repin the stay in its original position.

I have solo righted an Inter 20 numerous times ,with its 32 ft mast as compared to the much heavier H-18 w compit at 28 ft. The lightweight aspect of a CF mast is one of the best safety feature a cat could have .

Some very smart CF mast builder should offer replacement carbon fiber comptips for H ,--they would weigh half !!
and be much easier to right ,-no bob would be needed -
They would not be H-CLASS approved -however if that is any concern .

The carbon fiber comptip replacement along with new sq top main would increase performance speed and safety .
Pitching Moment for sailing craft is measured in ft Lbs
if you reduce the weight by 5 Lbs at an average height above deck of 20 ft that is ? --100 ft lbs of pitching moment .---How much more stable and better preforming would the 18 be without a heavy mast and bob ? that would often prevent the capsize in the first place.

There is an 18 sq locally that uses a CF top section epoxied in on lower alum mast that works perfectly still 15 years latter.
CF comptip replacement would be a nice way to really upgrade older existing cats and make them faster and safer.