Good morning,
I'm about to go in for my 6th trip, but I have yet to figure out the best way to travel with leashes. I am going for a week, so I have the bait king leach locker which can hold a lot of leaches. It works fine to carry it with a string tied to the handle during portages. My issue is when canoeing. If I am out fishing, I leave it dragging behind boat, it's slow, but at that point it's not a concern (or I have a smaller container that i fill with the day's quota).. but when I am paddling long distance.. especially on the first day, it slows you down a lot.. so I tried to put in in the canoe, but it's kind of tippy .. and it's not sealed, so it drains out if it tips.

I've tried clipping it to a gunwhale, but it slides to it's side, tips over and drains out (see picture) . Is there a trick anyone can share?

SHould I transfer them a nalgene bottle with holes?

I leave them in the sealed plastic bag and transport them in a pack on day one. They go in the leech locker upon arrival at my destination. I then use the bag as a seal by placing over the locker and screwing on the top if traveling to a new destination.

Well that makes sense .. so can they survive 8 hours like that?
So, if I hear you right, they come in a special bag that lets oxygen through?

I agree with Brux for the travel idea. Leave them in the bags on the way in. On a long travel day (have only done this once), I opened them into the locker, put it into the lake to change water, and then poured them back into bags again and tied them up for the rest of the trip. On all other trips have traveled 5-6 hours with them in the original bags and water. The leeches were just fine. Could put them back in bags again if changing sites too (as long as you don't rip the bags).

Get a Leech Tamer and pack it in a ziplock bag whenever traveling and portaging. Change out some water every 3 or 4 hours. When fishing, put what you need in a sandwich baggie with a bit of water and leave the Tamer at camp.

https://www.cabelas.com/p/lindy-leech-tamer?ds_e=GOOGLE&ds_c=Cabelas%7CShopping%7CPMax%7CFishing%7CGeneral%7CNAud%7CGoogle%7CNMT&gad_source=1&gad_campaignid=20046765526&gclid=CjwKCAjwuIbBBhBvEiwAsNypvb4JPnzPS2BvRKHK8F_LaxHuU71CKRauK5ir1qn2L42WEsy1IPHxbhoCMU4QAvD_BwE&gclsrc=aw.ds

I have the bag placed in the leach locker when they fill it at the bait store and have them pump air in the bag with it in the locker. This may not work on a hot summer day, but on cooler trips they will be fine the first day traveling. If I buy the leaches the evening before I put the locker with the leaches in a fridge or cooler over night. With the sealed bag inside the locker you can pack the entire thing in the top of a bag, no worries about holding on to it on portages.

I never drag behind the canoe. I have a cord with a small carabiner attached to the locker. While traveling I keep the locker at my feet in the canoe, dumping and refilling the water occasionally, maybe once an hour, to keep them cool. Always place in shade on portages and leave in water while at camp. I have never had any trouble keeping the leaches alive.

Just put them into Nalgene bottles. I have a couple of old ones that I use for transporting. Keep the leech tamer packed until you hit camp. Leeches are super durable and will keep just fine on an 8 hour travel day if you change out the water every hour or two.

I use a 1/2 gallon thermos like this.

I'll switch out the water a couple of times a day and it helps keep the temps down, which are the issue.