Peter yawned as he lay down on the rather comfortable bed that was included in his cabin on the Sea Mare. It hadn't taken long for him to get everything he wanted in town, and he was right about being poorer for it now. Still, he had a quarter of a million Belly left and that should last him a good while. He'd sell more gold on the next island to get some more Belly in his pocket, if he felt he needed it.
He'd even gotten free passage on the Sea Mare once the captain heard he was a doctor. Though it was on the condition that he treat the crew and other passengers for free. Though he would get paid for the cost of any medicines or materials he used. It had required Peter to buy stuff he couldn't produce on his own, like gauze, tape, suture needles and thread, and so on so he could do his job. Sure he could make a potion to deal with just about anything, but he wasn't about to advertise that particular skill! The last thing he wanted was for rumors to find their way to the marines or world nobles!
So, he put together a basic kit in a classic black bag and was ready to treat just about anything common. Mostly he just expected things like abrasions, contusions, and lacerations. Maybe the occasional cold as well since the journey to Cross Island was going to take a few weeks. He was in no particular rush. Luffy hadn't even started his journey yet so the world hadn't lost its mind yet either.
Deciding he'd spent enough time just lazing about in his bed, Peter got out of it and opened his hammer space. He collected a few things, took care of his necessary morning rituals, and got ready for the day. For him, the day didn't have much to it really. Unless someone got sick or hurt, all he had was free time. Since that was the case, the obvious thing to do was to train!
Yeah, he might be able to cheat a LOT thanks to his Essence and it's bullshit, but it didn't stop him from having to actually put in some work. Now, there were potions that could make him stronger, faster, and so on, but there was a small problem with them, they didn't automatically give him control over his new abilities. He could make himself as strong as an un-nerfed Superman, but he'd end up destroying everything he touched due to his lacking control. No, it was better to work and earn the strength.
That didn't mean he couldn't cheat to make the work easier or give him more gains!
To that end, he pulled out a blood red potion and downed it with a grimace. Next was a forest green potion that almost made him gag, it was so foul tasting. They were both worth it though! The first potion was a muscle repair potion while the second was a stamina regeneration potion. Together they allowed him to work out for hours straight with no downsides! He'd be just as fresh after a thousand push ups as he would be rolling out of bed.
Truly, potions were awesome.
The last thing he retrieved was a ring. The ring was enchanted to allow him to control the amount of resistance his body had to move against to do anything. He'd contemplated making one for gravity, but he didn't need that yet. Resistance training would be extremely effective since he was basically a normal person. He took a breath and activated the ring...
"Nothing's happening."
He frowned before realizing he needed to actually try moving. Annoyed with himself, he dropped to the ground and began doing some push ups. He immediately noticed the effect of the ring, it was too strong as he could barely move himself, so he lowered it to where he still had to strain but it wasn't nearly impossible to move.
He worked out for the first half of the day, push ups, sit ups, and especially squats. He fully intended to teach himself and then master the Rokushiki. Not because he had to or for any major reason, but because he wanted to! He was in the One Piece world dammit! Even if he could give himself the ability to fly it wasn't nearly as cool as using Geppo!
Besides which, he wasn't really able to make the potions and droughts that would allow him to modify his body heavily. It was entirely possible for him to make himself into a pure bred Saiyan, or give himself the genetics of Uchiha Madara and Senju Hashirama to become the ultimate Naruto-style ninja. He could give himself Kryptonian genetics and make himself genetically the son of Superman. The possibilities were literally limitless because their blood counted as an ingredient and could be summoned!
He just lacked the necessary lab equipment to make the complex concoctions that would let him do so. On top of which... well it might sound stupid but he didn't really want to give up his humanity. The human body in the One Piece world had nigh unlimited potential. Sure he wouldn't mind tweaking it a bit to make it more efficient and better, but he didn't see any reason to completely replace it.
He would definitely tack on a few things first chance he got though! He might not want to be a pure saiyan, but he wouldn't mind the Zenkai Boost or the ability to have transformations to boost his strength. He wouldn't mind having Sharingan eyes and Chakra to do ninja magic with. He wouldn't mind being able to absorb sunlight like a Kryptonian to replenish his strength. He just didn't want to stop being fully human.
None of that really mattered right at that moment though. He still needed better brewing equipment.
During the afternoon he took the potions again and only stopped working out when he had to treat a couple of small injuries and one case of sea sickness for another passenger. A simple potion he'd made for himself, just in case, was given to the individual to cure the condition permanently. He had no idea if he'd get seasick or not so he'd made the potion ahead of time just in case. As for the injuries, they were minor, nothing even requiring stitches, just some disinfecting and a quick wrap. Still, it proved his claims of being a doctor more than his ability to use big complicated doctor terminology had. You know, like calling a small cut a 'minor laceration'.
The rest of the journey to the next island on the trading ships route was spent in much the same manner. The weather in the blues was stable and the crew was well trained minimizing the risks of injury. No one got sick, either. This left Peter with nearly a week of not much to do but work out.