OP: Bunch of good discussions here already on heaving to and heavy weather
tactics in general. Give those a shearch. Worthwhile reading.
Also see Pardey's classic book "Storm Tactics". Their chosen method is to heave to, but assisted by a sea anchor
. This has caused much confusion in discussions because most think of heave to as under sail only.
Ive hove to on a lot of different boats in different conditions (used to teach a heavy weather seminar so got to do it a lot). As mentioned, every boat is different so getting to know the boat before needing to heave to in anger is important.
Worst Ive ever hove to in was 65 knots sustained, gusting to 85, seas about 25' and a little confused, but most not breaking heavily. A bit over 24 hours. Quite comfortable, we were able to nap, make coffee & meals
(maintained watch too though). Only took one or two breakers over the decks, battened down tight so not an issue, but a little disconcerting to watch green water
over the hatches from the inside though! This was on a modified fin keel
(fullish fore and aft) 37', cutter
rigged mono. We initially ran with this storm, because it developed suddenly and was unforecast. Ran, got more sea room and out of shipping
lanes, and then hove to and rode
the rest of it out. So, one tactic is not mutually exclusive of another...it depends on circumstances, crew, and the boat.
Have hove to on cats too in winds to about 50 knots, seas to about 12'.
Most often just heave to to ride out a passing strong squall.
Assuming the given boat heaves to well then I think the primary limiting factor is sea state. Wind
oppossing seas (unusual) or multiple wave trains from different directions could make heaving to untenable.
One of the most miserable nights Ive spent at sea was after a storm...calm wind, but signficant confused non breaking swell. Not possible to heave to or maintain a comfortable attitude...just lie there and roll heavily in random directions. Fortunately, it was just for a few hours waiting for dawn to make an unfamiliar reef entrance.