Littlest Brown Book - Encounters at Sea for Not My Destination

My upcoming Littlest Brown Book campaign, Not My Destination, has a decent naval component - much of the stereotypical wilderness between the players' starting town and the central dungeon will be open ocean. While the Littlest Brown Book comes with random encounter tables for rivers and swamps, it does not include one for the sea - so here is my own hacky attempt (I'm not kidding about hacky - this is basically just Rivers but without the things that need "land" to "live" and with some more human encounters, and on 2d10 for some good ol' probability).

This'll be my first campaign using lair chances - that'll be neat. Hopefully. 

2	The lost ancient treasure ship (i.e. dungeon) Column of Electrum Thrice-Bound in Tin.	12	2d8 Giant Fish
3	1d8 Giants (30% in lair - else on a single Giantish catamaran)	13	2d8 Giant Snakes
4	3d10x10 Pirates (15% in lair - else on 1d4 black iron vessels. The distinction between “pirate” and “buccaneer” is allegiance to seething Chaos - Buccaneer leaders are always Fighters and may be Neutral, but Pirate leaders are always Chaotic Magic-Users of the Black or Red Schools).	14	1d4 Manticores (25% in lair)
5	3d10x10 Mermen (15% in lair).	15	1d6 Wyverns (60% in lair)
6	3d10x10 Buccaneers (15% in lair - else on 1d4 wooden vessels)	16	1d20 Rocs (20% in lair)
7	A trading vessel, fat with [whatever the Type A (Water) treasure happens to generate] and guarded by 3d6x10 soldiers, half crossbowmen and half heavy footmen.	17	2d8 Giant Octopi
8	A rival adventuring party (1d4 levels of Fighter and 1d4 levels of Magic-User split between 2d4 people) sailing along. (I'm sure at some point I'll put some premade rival parties together, but just in case I need one quick...)	18	1 Sea Monster
9	A warship, hunting pirates and rescuing the stranded.	19	1 Dragon Turtle
10	1d4 small boats with 3 fishermen each.	20	1d4 Dragons (60% in lair)
11	A previously-met NPC or pursuing encounter. If neither is applicable, result 10.