Move rocks:
Press X + R and press Left or Right when over a rock to move it.

Hidden audio:
Place the game disc in an audio CD player and play track two to hear a hidden message.

Quick evolve:
When you play the game, you will see a shell at the bottom of the tank. Keep tapping the shell until it starts to eat your newborn Seaman. After they are eaten, tap the shell more until the squid completely comes out. It will squirm, and eventually after tapping it enough, it will die and the baby Seaman will appear and will be in the next stage, Gillman. Hold A while talking into the microphone to speak to your Seaman.

You do not have to tap the glass for a long time. All you have to do is tap the glass where the Nautilus is located. Let it eat all your "Mushroomers", then stop tapping. It will die soon after that and you now will have "Gillmen."

After completing a session, press X + Y + A + B + Start to reset the Dreamcast instead of turning the system off as prompted. Set the Dreamcast's system date twelve hours ahead (and change the date if required). Note: The tank will also not be maintained for that amount of time.

Turn on Dreamcast with no game disc and click on settings. Go to time and date and advance the date ahead by one day.

When setting the system time ahead to speed up evolution, be careful if going forward two days or more. It is possible that your Seaman might be dead or in serious condition. Also, you cannot go backwards in time because the game marks it in the VMU.

Dancing Seaman:
Complete the raising process until your Seaman is in the wild. When he is in the forest, press R to tap the glass and make a maraca sound. After doing this continuously you will hear drums -- this is when your seaman will start dancing. It also shows the credits and he will make remarks after you do this awhile.

Talking To your Seaman:
These are most of the words you can teach your Seaman. It is good to talk to your Seaman frequently. You need to teach them how to talk. Try to talk as clear as possible. Hold the A and talk into the microphone. The Gillman stage is the stage when it will first start to talk. Use these words when talking to Seaman: Hi, Hello, Hey, No, Yes, Seaman, Fish, Fun, Play, (and more). Experiment, but do not call it bad name or it will become unhappy. Also, remember to feed it once every day or when it is hungry.

Building a food supply:
If you happen to run low on food (Moths and Caterpillars), feed your Seaman a spider. They will get sick and will not require food for a couple of days. In this time you can allow a moth to lay eggs, then put it back in storage. Wait for eggs to hatch, place the two grubs in storage, make moth lay more eggs and repeat. Do this for a few days to build up your food supply.

Unlimited food:
Note: This trick requires two VMUs. Start and save a new game using a second VMU. Connect this VMU to a VMU that has an ongoing game. Transfer the food from the new game to the ongoing game. Repeat this as needed for unlimited food.

Give Seaman a new name:
After naming your Seaman the first time, repeatedly ask "Do you love me?". Eventually, you will be able to change the Seaman's name.

Special responses:
Tell your Seaman to "Eat sh*t". He will respond with "Ask and you shall receive" and promptly defecate on the glass window.

Keep using the words "English" and "America" when talking to your baby Seaman. He may respond with "Why do Americans always think that everyone speaks English? Sheesh!". More often, he will respond with "What for?" or "What's the point?". Respond with "That's what we speak in America" to get the first response.

Hint: Make the spider disappear:
After placing the spider in the aquarium, do the following if you want to lower the risk of Seaman eating it and getting sick. Place the spider in the tank, then press Start and chose "End" on the menu. Whenever you are at the screen where it tells you to turn the power off, press Start to return to the game. When you return, the spider will be gone and Seaman should not have eaten it.