Ugh, I feel your pain. Here’s some suggestions.

Talk to your rowers

Ask them individually what they want/need to hear and when. Does one of them start to forget his body positions as he gets more tired? Does another one just need you to ride his ass so he doesn’t quit in the last 300? Take notes and write it all down in your notebook.

Related: Do you recommend carrying a small pocket notebook or having a regular size notebook for notes? I currently have a pocket notebook during erg pieces to jot down splits and times. How do you organize all your thoughts and coxswain information?

Be aware of the rowers who don’t want you to say ANYTHING to them

Erging is a different beast than the boat and everyone has their own way of tackling it. If a rower yells at you to go away while he’s erging or tells you beforehand that he doesn’t like being coxed while he’s on the erg, respect it. Don’t take offense or ignore their request. They get themselves in that zone and you coming up behind them and reminding them about leg drive and such can throw them off.

Don’t try and correct their technique in the middle of the piece

If they haven’t figured it out by now, their times will reflect it and their bodies will feel it. Only tell them what you would tell them in the boat.

Drive: connect with the feet, press, feel it in the lats, etc.
Recovery: control, light on the seat, steady speed into the catch, sequencing, etc.
Body prep: body set early, get the hands and legs to speed, etc.
Bodies: chins up, cores tight, relax the upper bodies, stay light (especially important as they get towards the end and the bodies become sluggish), BREATHE, etc.

Motivate them without being a cheerleader

There are few things in rowing I hate more than perky, peppy, cheerleader coxswains. Get under their skin. Push them. Remind them what they’re doing this for. Are they trying to get one of the top eight times to be in the first varsity boat? Remind them of that when they’re starting to give in at the end. Tell them this is what they’ve been working for over the last few months, do NOT let the last 500m keep them out of this boat. Are they setting out to PR? Tell them to pace themselves, let the time come to them, not them going to the time. Are they trying to lower their times so they can submit them to colleges? Figure out what their top school is and use that to motivate them. When they’re looking particularly strong, get behind them and say “YEA!! That’s what a Dartmouth man looks like!” or “That’s how a Cal Bear attacks it!”.

Know the “science” behind erg strategy

When should they sprint, when should they “make a move”, etc. so you can make the appropriate calls when you cox them. This is also something they should know. Each rower might have their own strategy or your coach can give them a strategy, but it’s up to you to know whatever that strategy is. One rower might say he wants you to come over at 1000m to go to give him a 20…he’s relying on you for that, so you’ve gotta know WHY he wants it and be prepared to give it.

The first 500m, they should go ham just like they do at the start of a race. Get a good start, take a high, hard 20, and then another 20 to settle into their pace. If the pace is capped, make sure no one goes higher than that. 32-34 is probably all the higher they need to be going, although it varies by person.

By the middle 2000 (4000m – 2000m) they should have found a pace and settled into it. Make sure no one is flying and dying. They’re going to start getting really, REALLY tired as this middle 2k progresses because of the lactic acid building up in their systems. This is where you’re going to have to start pushing them and motivating them to not hit the wall – they’ve got to knock it the fuck DOWN.

Watch their splits and make sure they are sustainable, but not 30 seconds over where they should be. If they need to be pulling 1:45 splits, make sure they’re not pulling 1:49. If they back off a few splits during this middle part, the chances they’ll be able to get back down to the original split is going to be nearly impossible (from a physical standpoint but more so from a mental standpoint).

Around 1500m to go they should start pushing the splits down little by little every few hundred meters. Don’t “save” anything for the sprint. If they’ve “saved” their energy, they’re going to have too much to make up in order to get manage a decent time. Remind them of that. Don’t let them fall behind.

Start pushing that split down and then once they’re around 350m to go, drive up the stroke rate and fucking DROP THE HAMMER on the splits. EVERYTHING they have left should be going into this last 350m and it’s up to you to pull that out of them because at this point, if they’re pushing themselves the way they should be, they’re going to want to die.

Pay attention to your tone of voice

If you sound bored when you’re coxing them, they’re not going to listen to you and it can actually drag them down. You’ve got to stay upbeat, concise, direct, and have a good inflection in your voice. When you’re coxing individuals, you don’t have to yell at them 100% of the time. Get right by their ear when they’re at the finish and talk quietly but intensely to them. The person on the erg beside them shouldn’t be able to hear them. Talk quietly for a few strokes then say something like “Now GET IT” or something similar that causes you to raise your voice. You only really need to raise your voice if you’re walking behind them and see they’re going strong (YEA whatever their name is) and when they’re about to sprint (NOW’S THE TIME TO GO!). The rest of the time should be about 75% intensely quiet and 25% intensely loud.

I usually spend more time walking around just quietly observing during erg tests than I do talking to the guys. I’m gonna get more out of doing that than they are from me saying something in their ear (most of the time) so I only try to say something if it really needs to be said.