How to Set Up & Use TowCal

TowCal is a hitch calendar built for towboat and offshore crews. Tell it your rotation once and it lays out up to 18 months of on/off days, estimates your paychecks, and keeps your reminders, credentials, and planning tools in one place — all stored privately on your own phone or tablet (it runs native on iPad and Android tablets too). Here's how to get it dialed in.

1. Quick start — 4 steps

You can be up and running in a couple of minutes:

1

Pick your hitch — which rotation are you on?

On the ⚓ Schedule tab, tap your rotation from the presets — they're grouped by trade:

• ⚓ Towboat / Inland (US): 20/10, 28/14, 20/20…
• 🌍 Even-time / International (offshore, North Sea, EU, Australia): 2/2, 2/4 Norway, 4/4, 1/1 month…
• 🇦🇺 FIFO / Swing (Australia fly-in fly-out): 2/1, 8/6 offshore…

Run something different? Tap +/– Custom and type your own. Work a regular Monday–Friday job or an irregular schedule? There's a Work Mode toggle at the top of the same tab for shoreside schedules too — set your work week and on-call rotation, and the 4 major holidays (New Year's, Independence Day, Thanksgiving, Christmas) pay 1.5× automatically when you mark them worked on the calendar.

Example: a 20-and-10 towboat rotation — tap 20/10 and it highlights.

2

Tell it how your crew-change days fall

On the ⚓ Schedule tab in Settings, answer "How do your crew-change days fall?"

• Crew change on only one day? If you always get on and off on the same weekday(s), choose Same days every hitch. The day count flexes — a 20/20 reporting on a Tuesday gets off the Tuesday about three weeks later.
• Crew change on two different days? If your crew-change day alternates between two weekdays, choose Rotates between 2 days. Then pick the day you go back to work and put that day first in the "Get-on lands on either" row — the get-off row mirrors it, like the picture below.

Example: your next get-on is a Tuesday, so Tuesday goes first — get-on lands on Tuesday/Friday, get-off on Friday/Tuesday.

2. The five bottom buttons

Using the Load Calc

Tap 🛢️ Load Calc and it takes about ten seconds:

1. Pick your barges from the presets — 1×30k, the common 2×30k tow, 1×10k, 2×10k — or type a custom barrel total.
2. Set the dock transfer rate the dock gave you with the slider, or tap a preset (slow dock 1,000 · typical 2,500 · hot dock 5,000).
3. Leave topping off checked (slows the last 10% to half rate, like you would on the header) and set the shift time between barges if you're loading more than one.

You get the full run time hooked-up-to-topped-off, total barrels, effective rate, pumping time per barge — and a finish-time planner: tell it when you start your watch and it tells you when you'll be done.

Pumping estimates only — gauging, line displacement, stripping, paperwork and dock delays aren't on this clock. The max transfer rate on your Declaration of Inspection governs, always.

Using the Discharge Calc

Tap 🔽 Disch Calc when you're pumping off. Instead of a barrel rate, it works the way you actually watch a discharge — feet in the tanks and how fast a foot drops:

1. Pick your barge — 30k or 10k barrel, then the tank shape: a 30k runs 4 sets bow to stern as either 6 tanks (1·2·2·1) or 8 tanks (2·2·2·2); a 10k runs 3 tanks down the centerline or 4 tanks in 2 port/stbd sets. Loading two? Tap 2 Barges and both hulls show on the diagram.
2. Set the feet in each tank right on the barge diagram — scroll the mouse wheel over a gauge or drag it on the touchscreen (0–50 ft, half-foot steps). Set one gauge and tap ⇄ Match to copy it to every set.
3. Enter your time to discharge 1 foot — just time the gauge dropping a foot, that's your number — plus an optional stripping time allowance for drying the tanks at the end.

You get the total time to pump everything to zero, and the same finish-time planner as the Load Calc: enter when you start and it tells you when you'll be empty.

Pumping estimate only — gauging, paperwork and dock delays are not on this clock.

3. Using the calendar day-to-day

• Switch views with the pills at the top: Agenda, Week, Month, 3 Months, 6 Months, or Year. The year views are great for planning doctor's appointments and vacations around future hitches — you can look up to 18 months ahead.
• Holidays at a glance: the major holidays coming up show as words right above the calendar — green means you're home that day, red means you're working or it's a crew change. Past holidays drop off as they pass.
• Tap any day to see what's on it, or to add a note, appointment, or reminder to that date.
• Add an event fast: tap + Add and type it like you'd say it — "Lunch with Sam Tuesday 1pm at Olive Garden" — and TowCal fills in the date, time, and place for you.
• Ride-over or sick day? Tap that day and mark it. TowCal adjusts your pay estimate to match what actually happened.
• Today button jumps you back to the current date from anywhere.

4. Setting up your pay

In Settings → 💵 Pay:

1. Enter your day rate at the top of the tab — plus per diem if you get one (it's added on top for each day worked and isn't taxed in the estimate; leave it blank if you don't), and your ride-over pay. Mark a ride-over day on the calendar and TowCal adds one daily rate + that amount to the pay period; mark a home-early/sick day and it subtracts one daily rate.
2. Set your pay schedule. Under Pay Schedule, pick how many times a month you're paid, then the day of the month for each check — say the 5th and the 20th. Choose 31 (End of month) for the last day; it adjusts automatically for shorter months.
3. Tell it what each check pays for. For each pay date, tap the start day then the end day of the work period that check covers. Checks are usually delayed, so a period can run through the previous month — e.g. the check on the 5th pays for the 16th → end of last month, and the check on the 20th pays for the 1st → 15th.
4. Flip on your deductions. Toggle whatever comes out of your check — medical insurance, 401(k), taxes (a flat percentage), savings, emergency fund, FSA. Leave the international/statutory ones off unless you need them.

Projected paychecks then show up on the calendar and in the Pay panel, itemized on each payday.

5. What's in Settings — tab by tab

Bank balances, debt payoff, and Tide Turner are what-if planning tools only — not financial, tax, or legal advice.

A look inside a few of them:

Setting up Credentials — renewal reminders on autopilot

On the 🪪 Credentials tab:

1. Press United States (or your region — Universal STCW, Europe/UK, Australia/NZ, etc.) and it loads the standard credential list for your trade: MMC, TWIC, medical certificate, and the rest.
2. Fill in your expiration dates on each card.
3. Remove any credential you don't use — tap the ✕ on its card.

That's it — the app automatically reminds you 1 year before the due date, then keeps repeating monthly until you renew. Your renewals also show as countdown tiles right at the top of the main screen, so you see "renew in X months" every time you open the app.

6. Making sure reminders fire (Android)

Android phones aggressively pause background apps to save battery, which can stop reminders from firing while TowCal is closed. A one-time check in your phone's Settings app fixes it:

1. Allow notifications: Settings → Apps → TowCal → Notifications → on.
2. Let it run in the background: Settings → Apps → TowCal → Battery → Unrestricted (some phones say "Don't optimize" or "Allow background activity"). This is the #1 reason reminders don't fire.
3. Samsung phones: Settings → Battery → Background usage limits — make sure TowCal is not in "Sleeping apps" or "Deep sleeping apps."
4. Do Not Disturb: if DND is on, add TowCal as an allowed exception or reminders can be silenced.

Then test it: in TowCal, open Settings → More → Reminder & notification settings and tap Test — a reminder should appear within a few seconds. A scheduled reminder arriving a few minutes early or late is normal; Android groups background alarms to save battery.

7. Sharing your schedule

Tap the Agenda pill at the top of the calendar and tap Export PDF — you get the next six months of your schedule on one clean page, ready to text to your spouse, email to a doctor's office, or print for the fridge. Your phone's share sheet pops up so you can send it anywhere: text, email, print, or save it to your files.

8. Subscription, free month & promo codes

• Pricing: $2.99/month or $19.99/year, billed through your app store. New annual subscribers pay $14.99 for the first year, then $19.99/year.
• Free first month: every new subscriber gets their first month free automatically on the monthly plan — no code needed. The subscription screen shows "Start Free Month" when it applies, and you're not charged until the month is up.
• New phone? Open TowCal and tap Restore Purchase on the subscription screen while signed in to the same App Store or Google Play account you bought with.
• Promo code from a giveaway? Redeem it via Settings → More → Redeem a promo code.
• Cancel anytime: iPhone: Settings → your name → Subscriptions. Android: Google Play → Profile → Payments & subscriptions → Subscriptions.

9. Where your data lives — and how to back it up

On your phone — period. TowCal stores your schedule, pay setup, and everything else locally on your device and does not send it to us or anyone else. See the Privacy Policy for details.

• Backup file: in Settings → More → 💾 Backup & Restore, save a backup file of everything — schedule, pay, credentials, journal, goals — and keep it somewhere safe (email it to yourself or drop it in your cloud drive). On a new phone, upload that file to restore.
• iPhone & iPad: TowCal also keeps a copy in your own iCloud automatically — nothing comes to us. Install TowCal on a new iPhone or iPad signed into the same iCloud account and it offers to restore your setup on first launch.