troll speed depends on sea conditions, wave direction, and particular boat preference. circle hooks has really changed the game for billfishing in terms of offerings, and a big learning curve in rigging bigger circles for bm etc. I have been billfishing for 20 yrs, though i fish all major tourney, the pesky wm is why I continue to fish. they are so hard to consistently catch, but love it.
my wm spread is a five rod spread of all dink ballyhoos, maybe a big bm offering off right short rigger but a plethora of pitchbaits in the cockpit. the difference in marlin fishing is the boat, u need to hum, you need the spread, you need to pull the dredges and teasers. you need them to get interested to raise to boat, then you have to have eyes constantly on spread, each man guarding a rod and spot fish. Marlin fishing is all about paying attention, as the hook up ratio greatly improves with seeing him vs him hanging himself.
I denied it for the first eight years of marlin fishing that the size of the boat is important. mostly bc i only fished boats in the 28 to 35 ft range. but as i was able to purchase larger boat the numbers of whites caught and released grew expontentially. The imprint of the boat in the water is very key to white marlin fishing. I hate the thought of money=success in wm fishing but the sad truth after many many years, many of those frustrating in not having alot of success. but you need the mullet dredge on one side, the ballyhoo dredge on the other side, two sets of large squid teaser chains dropped back a good distance and a man in the tower who eats, sleeps, shits, pees, and whatever else he needs is all done up there, bc if eyes arent watching so minds as well just go to the beach for the day.
if you plan on wm fishing from a center console with no tower it will be very tough and frustrating. you will ask yourself alot of questions of why am I not seeing fish when other boats are seeing five per day or more. from a center console i may mix the spread alittle more, keep it diverse, pull two bm baits, to troll alittle faster, create more vibration and commotion and let the bm come in hot and hook himself. then use the mauneverability of center console as advantage. a more diverse spread will equal more chances of actions rather then counting on only wm because two things are probablly occurring: one, he is back there, u just dont see him and he swam away or stripped your bait. two, your not raising fish to your spread on account of boat traffic in the area and the fish are going to bigger footprints in the water, ie. bigge boats. best bet is fish away from crowd and cross fingers
good luck